Fix leaked globals.
Added the new door textures
Pine tree, pine needles, pine sapling and pinewood nodes, including textures by Splizard and Cisoun
Fix some undeclared global variables
Fix various fire sound bugs
Add missing groups to pine sapling
Add all saplings to group sapling
Merge remote-tracking branch 'minetest_game/master'

Conflicts:
	mods/default/crafting.lua
	mods/doors/textures/door_brown.png
	mods/doors/textures/door_grey.png
	mods/doors/textures/door_steel_a.png
	mods/doors/textures/door_steel_b.png
	mods/doors/textures/door_wood_a.png
	mods/doors/textures/door_wood_b.png
	mods/stairs/init.lua