readd submodule boats+farming

Some nodes with the snappy group (wool, glass pane, seeds) were missing
sound when dug with a sword.
Adding the sound causes it to be used for glass pane, so define a 'dig'
sound in the 'node sound glass defaults' table, use the footstep sound.
Adding the sound also causes it to be used for seeds which deliberately
have no dig sound, so add an empty sound override for seed dig.

Reduce the gain of the glass footstep sound which was excessively loud.

Add some freesound members to license.txt.

Handbrake was barely noticeable and fairly useless.
Equalisng with brake rail deceleration makes it more intuitive to use
and easier to judge stopping distance.

This is slightly modified after #1279 - the setting for furnace
timer was removed and hardcoded to 1.0s, which is the old furnace
timer interval.

Previous code:
Used looped sounds without attaching them to objects or playing direct
to players.
The looped sounds are not 'stopped' when players leave the area.
These may be causing the bug where sounds are heard at extreme
distances.
Entering a world with already present flames results in silent flames.
Sounds are often played at a large number of points in a 6 node lattice.
A large fire is reported to cause a high load, disabling the sound code
is reported to help this.

New code:
Optional flame sound to not interfere with ambience mods.
Permanent flame now has sound.
For multiple flames, sound is positioned at the centre of all flames, and
has volume determined by flame number.
The original freesound 'large fire' recording was used to create 3 sounds
that play at random for a non-repetitive effect. At low volume it is
suitable for small fires.

Original sound files and sound function (as an empty function) kept
temporarily to reduce disruption.

Reduce gain of flame extinguish sound.

Also sets creative:all as default inventory page
Fixes #1423

Some GPUs cause visual bugs when mip-mapping is used with indexed textures
that use alpha. Because leaves are sometimes rendered opaque it is even
more important to keep these as RGBA to preserve the correct background
colour.

Papyrus:
Make base node dirt instead of dirt_with_grass. Formerly the exposed
dirt would change to grass but the new grass spread ABM now prevents that.

Waterlily:
Don't specify a water_source node in the schematic, as it may be used in
river water. It was not force-placed but should really be "air" prob = 0.

This changes the farming API such that any nodedef with paramtype2
and place_param2 are passed through to all the plant stages of the
farming plant.

This allows plants to use an alternative mesh for the plantlike
drawtype, and provide a bit of graphical variation in plants.

We enable this for wheat, using place_param2 = 3, which is the '#'
shaped plant mesh. If you would actually be able to give yourself
this plant in creative or through /give, you would also get the
same '#' shape.

This makes all the 3d torch selection boxes 1px oversized. Before,
they were inconsistently sized and too small for the upright torch.

Biomes:
Add 'sandstone desert', 'cold desert', 'snowy grassland'.
Rename 'glacier' biome to 'icesheet' biome.
Rename non-swamp 'swamp' biomes to 'shore' biomes.
Remove 'sandstone grassland' biome.
Rename 'stone grassland' biome to 'grassland' biome.
Edit biome points for improved similarity to Whittaker classification.
Change 'tundra' to bare stone with snowblocks.
Make dirt 'swamp' / 'shore' less deep.

Ores:
Make dirt blob ore biome-specific, limit to dirt biomes.

Decorations:
Make mushroom noise spread match that of appletrees as originally intended,
to have mushrooms spawn in darker thicker forest areas.
Add coral reefs in warm oceans.
Add bushes and acacia bushes.
Jungletrees in deeper water for larger swamps.

Register flower mod decorations in singlenode mapgen for use by
minetest.generate_registered_decorations, as in default/mapgen.lua.

Boats:
Previously, boats were not added to inventory in creative mode, fix.
In creative mode multiple boats will not be added to inventory.
Add comment.

Carts:
Set speed to 2 if punched by a non-player, to match the effect of a
player punch.
Add comments.

Fixes (I hope) #1420 (bad method call).

This commit makes the carts mod not add the cart
item to the player's inventory if running with
creative mode and the player already has it.

This is partly a workaround for a bug.
Climbs with continuous power rails were failing often due to
unexplained losses of speed leading to a reversal of direction.
The lack of acceleration on climbs meant that lost speed was not
regained.
Keeping cart speed at maximum on climbs helps reduce the chance of
reversals.

This also allows players to slowly accelerate up to full speed on a
climb without needing a horizontal run-up to reach full speed first.
It may not be possible to build the horizontal sections needed, or,
if players are replacing a previous carts mod their track
constructions, bridges, tunnels etc. will often not have the
horizontal sections needed.
Players will also sometimes need to place and enter a cart on a slope
and be able to climb.

Add tool break sounds to hoes and flint and steel.
Flint and steel: Reduce gain of use sound and only add tool wear
if not in creative mode.

- Improve arms attachment

  The arm bones were at an angle, so that the bones were difficult
  to orient correctly, as unintuitive combinations of angles
  would be needed to get the default orientation, or any other
  acceptable orientation. Moreover, a simple rotation of the arm,
  e.g. forward, would require all angles to be adapted, instead
  of just one.

  The ends of the arms bones were moved from touching the body, to
  the center of the arm, at an equal distance from the sides of the
  arm and the shoulder; the arm bone is now in the center of the arm.

- Fix body rotation

  The body was rotated 180° while the rest wasn't, leading to
  strange results when setting bone positions manually.

- Fix default rotation of limbs (manually positioning them in
  their default position would require an 180° rotation).
  Is is not know how this was fixed. Maybe just because the
  model was re-exported.

- The bone of the cape was moved to the center of the cape (it was
  at the edge). For some reason this fixed the 180° rotation of the
  cape when it was manually positioned (similar to previous issue).

The changes above fix most of the issues mentioned in #1376

- Add a player-model-specific workaround for the problem described in:
  https://github.com/minetest/minetest/issues/2813#issuecomment-198796927
  https://github.com/minetest/minetest_game/pull/1392#issuecomment-261669915

  During walking, attached tools would randomly switch hands. Walking also
  happens to be the only animation where the body does not move. Making the
  body move an imperceptible amount makes the issue disappear for the player
  model.

- Fix body vertex group: it no longer includes parts of arms and legs

Thanks to @stujones11 for these last two changes.

This code adds the key concept to minetest_game, and integrates it
with lockable nodes. Currently supported lockable items are the Steel
Door, the Steel Trapdoor, and the Locked Chest.

The goal of this modification is to introduce a fine-grained multi-
player permission system that is intuitive and usable without any
console or chat commands, and doesn't require extra privileges to
be granted or setup. Keys can also physically be conveyed to other
players, adding to gameplay and adding some personality that is
preferable to console commands or editing formspecs.

A skeleton key can be crafted with 1 gold ingot. Skeleton keys can
then be matched to a lockable node by right-clicking the skeleton
key on a lockable node, which changes the skeleton key to a "key".

Gold was chosen as it's currently a not-so very useful item, and
therefore it's likely that players have some, but aren't really
using it for any purpose.

This key can subsequently used by any player to open or access that
lockable node, including retrieving items from Locked Chests, or
putting items in them.

They key is programmed to fit only the particular locked node it is
programmed to. This is achieved by storing a secret value in both
key and locked node. If this secret value doesn't match, the key
will not open the locked node. This allows many keys to be created
for one chest or door, but a key will only fit one node ever. The
secrets are stored in node, and item meta for the key.

If a locked node is removed, all keys that opened it are no longer
valid. Even if a new door/chest is placed in exactly the same spot,
the old keys will no longer fit that node.

Keys can be smelted back in gold ingots if they are no longer useful.

The method of storing a secret in nodemeta and itemstackmeta is secure
as there is no way for the client to create new items on the server
with a particular secret metadata value. Even if you could possible
create such an itemstack on the client, the server does not ever read
itemstackmeta from a client package.

The patch adds an API that allows other nodes and nodes added by
mods to use the same keys as well. The method how to implement this
is described in game_api.txt. The mod should add 2 callbacks to it's
node definition. Example code is given.

Textures are from PixelBOX, thanks to Gambit.

Use travis' container-based infrastructure (no sudo)

This merges the current state of the well-maintained and tested
`torches` mod as I've maintained it for the last 6 months.

This started out as a thorough cleanup of 3D torches by blockmen,
where some of the initial code still remains.

The models were redone entirely from scratch and have been extensively
tested with dozens of animated textures converted with mcimport,
and look a lot better than the original 3D Torches mod.

The ceiling torch is retained and functional. The `wieldlight`
addition that the torches mod has was removed, since it relies
on wieldview to look decent. This can stay external mod code.

I've opted to move the torch nodes to a separate file. It's not
a lot of code but nodes.lua is already huge, and I wanted to
retain the copyright header and some of the readme.txt notes,
and this was the easiest way of doing it.

This code passes "default:torch" to nodes with on_rightclick,
fixing problems with itemframes. Essentially it has a more
elaborate item_place() routine to make sure we're not passing
the wall torch to nodes that may display it.

The ceiling torch is a separate model and not the same as the
floor model. That does mean that there are 3 models in this
mod.

Stereo sounds are not played positionally, which should never
happen. Convert this track to mono to fix.

This makes the itemstrings consistent over the whole file.

Plus one silent sound to break repetition 'default_water_footstep.4.ogg'.