These basic connected wall nodes automatically connect
to neigboring stone blocks, other wall blocks and anything
that's "cracky". The do not connect to wood (fences will do
that).

The walls are generated using a new walls.register() API.
Documentation on the API is included in game_api.txt.

This change requires minetest/minetest#3503.

Walls are added for all cobble stone materials. They generally
look best and are the natural use cases for these materials.

This fence gate builds on NDT_CONNECTED by assuming fence nodes will
automatically connect to it's sides properly. The fence gate will
open and close just like doors, with sounds, but it only opens one
way. The gate sticks out quite a bit and can be bumped into, so the
fence may be used as some sort of path switch.

The fence gate offers no form of protection and can be opened and
closed by anyone. This is done on purpose - the fencegate isn't
meant to provide protection from players, as fences can be
trivially jumped over. Instead, these fences should be used for
protecting crops from hungry sheep, or keeping rabbits in their
pen, or just decoration. Mods can also modify the mod to add
protection, of course.

A recipe is added to make these. It's 4 sticks and 2 wood (any)
as follows:

  stick  wood  stick
  stick  wood  stick

The collision box of the open gate is such that if two gates are
connected but mirrored (making an M shape) then you can walk a large
entity that's larger than 1.0 wide through the opening. The gate of
an opened fence can also be stood upon or bumped into.

I've mixed together some sounds to provide a somewhat light sound
experience, one that one would expect from a small gate latching open
and close.

This change requires #873, otherwise it doesn't connect to fences.

This changes the drawtype of fences to NDT_CONNECTED nodebox drawtype.

These nodes are drawn by the client with the needed connections on
the fly as the scene is drawn. There is no logic needed by mods to
modify the nodes.

These fences connect to (1) other fences, (2) planks and (3) tree
trunks, but nothing else. They do not connect to stone, dirt, wool,
etc. This is done by the "connects_to" parameter, which takes groups
and node names.

Due to the way textures are wrapped, we can make these nodes look a
lot better by giving them a special tile.

This change requires minetest/minetest#3503.

Books still don't wrap long lines of text properly so until this has been sorted out I suggest reverting back to a previous working formspec which lets players read books properly until a fix is found (and maybe scrollbars added to texarea's).  Also adding a recipe to blank written books.

https://forum.minetest.net/viewtopic.php?f=42&t=1523&start=500#p208773

Currently, doors can be placed inside others' protected areas. We
need to check protection for both bottom and top halves.

Add function to detect nearby snow to enable snow on sapling-grown pine trees
Correct 'place schematic' rotation parameters to "0" or "random"

In mgv5/v7/flat/fractal/valleys
Add missing noise parameters to pine logs for
density to vary in relation to pine tree density

As requested by @paramat.
Leaves are preserved by default and only decay when using place + sneak.

Digging a cactus leaves the branches hanging. With this change it will no longer happen.

This is an adapted version of #861 - by oleastre

Most mods had been calling `doors.register_door() with a door
name that included the "modname:" prefix, and we should continue
to allow mods to do so, without registering the nodenames created
in the "doors:" namespace.

The default case is to use the "modname:" prefix verbatim. If
mods or code calls this function without a prefix, then "doors:"
is automatically used.

Now that the namespace is corrected, the copy replacement ABM is
no longer needed.

This function maps doors.register_door to the new API as far as
reasonable. We can't map the texture, so we fall back to a default
texture. An error message is printed if mod writers did not provide the
needed new tiles field for the door. The created doors are functional
and a full replacement. Old doors are replaced with the new ones
through an ABM.

A previous fix overwrote the `def` variable during registration,
causing protected doors no longer to be placed with protection.

These sounds were perceived to be too loud in the
game. I've lowered them significantly but they remain
plenty audible. The dig sounds were very loud as well
so I toned them down as well.

This file is obviously out of place, as the engine does not
load textures, ever, out of a models folder.

Other mods may depend on knowing whether doors are placed
to setup additional attributes or perform node manipulations.

This is something e.g. mesecons does to connect circuits
to doors. This was tested with mesecons. Placing a door next
to a mesecon wire will make the wire automatically
connect, which was otherwise not happening.

And similarly, if we wield a door and right click any node
that has an on_rightclick() handler, call the handler
instead.

Just to be on the safe side, assure that none of this
code runs when right-clicking an entity or player, which
would likely crash the server.

Fold in PR #831 as well - prevent server crash on door
place on unknown blocks, by @tenplus1.

This code never allowed placing a door on e.g. a grass
plant. The code to handle this isn't that complex. With
this code, doors can be placed on flowers and on normal
node surfaces without issues.

Issue #811 - new gravel texture needed.

This texture was Gambits' PixelBOX gravel light texture. Gambit
posted that his texture pack is WTFPL:
- https://forum.minetest.net/viewtopic.php?f=4&t=4990&start=50#p141196

I've made significant modifications to this texture:
- slightly rotated and rolled some sections of pixels
- minor burn/dodge some pixels to keep high contrast
- removed lineair repeating effects
- etc.

Attribution is added back to Gambit. Thanks.

This allows mod makers to register their own recipies, including
none, to register doors.

Both the standing and sitting animations had misplaced curve
cusps that caused the end part of the animation to wiggle the
feet slightly back and forward.

I've fixed both animations parts and re-exported. Verified in-game
with multiplayer that everything was indeed fixed.

By adding the timer to the tnt:tnt_burning node it will help mods add the block and cause an explosion after 4 seconds instead of doing nothing like in it's current state.

This option is not documented nor is it used with any other mod in Minetest Game so why should it be used in TNT?

Spread ABM intervals evenly across 1 to 16 seconds
16s ensures no nodes are missed when player walks past
Adjust chance values to compensate, for identical action rates
Combine lavacooling ABMs into one, return to chance = 1
Grass growth: add 'neighbors = "air"' to avoid
processing the thousands of underground dirt nodes
Grass death: Reduce action rate to that of grass growth
Fire: Use chance = 1 for flame extinguishing
and flame removal when mod is disabled