- Allow rotation of wallmounted nodeboxes (signs) since they are
  now rotating properly.
- Instead of testing `ndef` several times, do it once, correctly.
- Simplify exception logic for nodes that have `on_rotate` set.
- For simplicity, return itemstack, always.
- Remove a useless nil check.

Some code was lost during a rebase of a recently merged commit (73e4666f).

Although the new aspen tree schematic only requires a radius of 2 the
many existing aspen trees in a world require radius 3.

Previously you could place junglegrass on dirt to convert that dirt to
dirt_with_grass, but this is unsuitable now that rainforest has a
surface of dirt_with_rainforest_litter.
Remove junglegrass from the 'grass' group.

Since meta secret field is blank on any keys (default:key) obtained using
/give, the game will crash if you attempt to use one of these. This follows
along the principle that the game should never have any reason to crash.

A simple set of biomes for now: Ocean, coniferous forest, grassland,
sandstone desert.
Update biome lists for blob ores and decorations.

Make sandstone desert filler 1 node deeper to match other deserts.

Instead of right click, the skeleton key is now a true `tool`
in the sense that it's default left-click action is to create
a key for the locked object.

This is far better than the outcome of the patches we've done
where the only way to create a key for a locked item was to
use sneak+rightclick. Now keys are perhaps a bit more sensible,
left for making keys, right for opening stuff with keys.

Fixes #1625

Migrates settings safely and evacuates the `homes` file
entirely over time.

Update readme.txt with new TNT crafting recipe.

Without this patch, any fire created(placed) by tnt explosions
will remain forever on the map.

Completes a forgotten update in 9d3a5263

This should be fairly cheap and pops off items if needed.

The table was generated using the old code. A table lookup
should be faster than lots of math and branches.

Allows us to drop `nextrange()` as well.

Allows rotating things like signs and torches. Axis rotation
rotates over all 6 faces, face rotation flips upside down to
flat on floor only, and of course in the 4 horizontal directions.

Made the code a bit more modular to account for different rotation
schemes. Should be easier to extend from here on to other needs,
and the functions can be reused by other mods for convenience.

Usage and tool break sounds were played at 'pointed_thing.above' which
can be nil if not pointing at anything or at an entity. This caused
sounds to be played to all players on a server non-positionally.

Fallback to player pos for sounds if 'pointed_thing.above' is nil.

Replace 'pt' variable with 'pointed_thing' in 'register_tool'.

Currently jungletrees and junglegrass use sidelen 80 for simplicity,
but this results in a more uneven distribution of decorations. A more
even distribution helps keep rainforest darker with a more unbroken
canopy.
This is also more consistent. 80 is based on the default mapchunk
size, all other decorations use sidelen 16 or smaller to divide into
any mapchunk size.

Denser jungletree for darker rainforest:
Highest 'jungletree' nodes now prob 255.
Add a 5th lower branch layer.
Increase lower branch layer y-slice prob to 191.

Aspen:
Extend trunk upwards by 1 node to reduce leafdecay radius to 2.

Pine:
Make lower trunk 1 node longer so that lowest branches are more often
higher off the ground, also to make pines taller.

Appletree:
Make 2 opposite branches prob 255, the other 2 prob 127, to avoid
trees with 1 or 0 branches. Therefore also add random rotation.

Increase to 5 ladders from 7 sticks.
More generous to help with vertical travel.

Divide the log core volume of 14 * 14 * 16 cubic pixels by the volume of
a ladder node with two 2 * 2 * 16 side pieces and four 2 * 1 * 16 rungs
(cut down to length 14), to get 12.25 ladders per log.
The recipe of 7 stick items is 7 / 16 = 0.4375 logs.
Ladders per 7 stick items = 0.4375 * 12.25 = 5.36.

Thank you to @ForbiddenJ for finding cause of the issue.

If 'node_box' is nil 'node_box.type' causes a crash.

Add desert and silver sand-related blocks, and stairs.

Also fixes the failing travis checks.

Utilizes the new key-meta (as with nodes) and the ability to set the description of an itemstack with the `description` meta key. Includes code to convert old metadata to new key-meta.

- beds
- boats
- carts
- key/skeleton key
- seeds

All these had on_place handlers that did not allow nodes with
an on_rightclick() handler to be used first (if not using
sneak). This code is taken from the torches mod and applied
everywhere.

This allows all these items to e.g. be inserted into the `frame`
mod's item frames.

Moist rainforest plant litter.
Textures by npx.

Utilizes several new features allowing the description of an item to be changed using the `description` meta key. This also moves keys from using the old single-value itemstack metadata system to the new node-like metadata system.

Return to previous parameters interval = 1, chance = 2.
Compensates for the increase in default active block radius.
Large amounts of lava cooling at once is known to overload sound
creation, producing error messages.

As part of the original plan for a new lightcurve.

With the old lightcurve lights were so dim all light sources had light
source level 13 or 14 to compensate, resulting in almost no difference
between torchlight and a maximum brightness light.

The new lightcurve makes all light sources effectively much brighter by
spreading visually-bright light further, torches are now slightly too
bright. So now we can reduce the light source level of torches while
actually making them effectively brighter than with the old lightcurve.
This also creates a desirable difference between torchlight and a
maximum-brightness light source.

This implements a node-timer based leafdecay mechanism, and exposes
an API to use it in mods.

The API is documented in game_api.txt.

`default.register_leafdecay(leafdecaydef)`

`leafdecaydef` is a table, with following members:
{
	trunks = { "default:tree"}, -- nodes considered trunks
	leaves = { "default:leaves", "default:apple"}, -- nodes considered leaves
	radius = 3, -- activates leafdecay this far from the trunk
}

The algorithm will drop `leaves` items in the area if no `trunks` are found
in the `trunk_radius` sized area around the position of the leaf. If a node
listed in `leaves` has a group `leafdecay_drop > 0`, then the item is dropped,
otherwise the item is removed but not dropped.

The algorithm also implements a value `default.leafdecay_speed` (default
15) which can be modified to increase or decrease of the leaf decay. The
algorithm will vary the actual speed a bit to introduce randomness.

Leaf decay is randomized by 0.1 seconds to reduce the chance that
decay happens many times on the same second interval. This requires
nodetimer_interval to be set to values lower than 1.0 to have an
effect.

The leaves will decay between 2 and 10 seconds after digging the trunk,
and happen at non-integer second intervals.

-- The API was added by sofar.

* rename to default.can_interact_with_node()
* pass pos instead of meta
* change order of arguments