Merge pull request #64 from Selat/key-value-storage

Key value storage
Invert xy param for math mapgen (rotate world)
Reverse path order
Support bug of previous pathfinder
Merge pull request #66 from Selat/pathfinder

Pathfinder
Add .db to kv base name
save players to ldb (WIP)
Close db
conf var enable_any_name
Settings json optimize
Fix lost change password button
Serialize player to json
Merge remote-tracking branch 'minetest/master'

Conflicts:
	src/game.cpp
Performance optimized button to button mask evaluation
intl in formspec
player name as std::string
support auth for any player names
Save favorites to json
Default value for password field
Dont stuck on error