fixes #2228

This is a rebased and slightly rewritten version of #2125.

Footstep sounds as sand or cubic coral nodes.
Dig and dug sounds as leaves but much lower gain to be suitable for
underwater.

Players can enter unlimited text into the field, causing lag and
potentially locking up clients. I have not found any negative effects
server side, other than the large storage needed to store the long
text.

The on_rotate function now checks the new param2 value to determine if a rotation is valid, rather than checking the rotation mode.
This is so screwdriver-like items with different rotation modes will not be able to rotate the bed into invalid orientations.

Previously they were not collectable or creatable.
A simple temporary solution for MTG 5.0.0.

Update was missing from 7fa03c7a

Fix small pine leafdecay: New schematics, new leafdecay radius 

Keep their definitions, to not break mods, but move them to legacy.lua.

Alter 'large cactus' schematic to place another force-placed cactus node,
to replace the cactus seedling on growth.
Make schematic 5x7x5 to solve rotation, placement and protection check
issues.
Add a y-slice probability for height variation.

Growth time is tuned to not make this a faster way to obtain cactus nodes
compared to normal cactus farming.
Seedling texture by Extex101.

Use sapling/seedling description in protection intersection message in
'sapling_on_place' function.

Allow mods such as protection mods to over ride on_rightclick.
Usecase is creating shared doors without the need for keys.

No longer use default_wood.png for one side of the bed head and
one side of the bed bottom node.
Add a new texture for the underside of both beds.

Fixes most z-fighting caused by underwater nodeboxes.
Special tiles were for 'new style water' (lowered water level) which was
removed a few years ago.

Fix slabs combining into a cube: Facedir is only set for the cube if it has
paramtype2 = "facedir". This avoids liquid appearing in connected
framed glasslike.

All stair/slab nodes with parent nodes that are rotatable (wood and bricks)
are reverted to not having world-aligned textures, to fix the breakage of
rotated stair/slab appearence in worlds.

Update, and add missing documentation to, game_api.txt.