Added 1.7 blocks and items.
Fixed some javadocs and deprecated isNaturalTerrainBlock(int).
Added 1.7.2 biomes and trees.
Added rotate/flip/cycle data for 1.7.2 blocks.
Allow forest generator to make trees under snow tiles.
The /green command no longer affects permadirt and podzol.

This behaviour can be overridden with -f.
Revert /up and /ceil command to use glass block by default. Flight can be done via -f flag now.
Added config option to set the default for the /up and /ceil commands.

The config option defaults to glass as that is consistent across gamemodes.
Use -f to force flight (if available).
Use -g to force glass.
Fixed CI link in readme.
Manual merge with remote repo.