Add entity health saving.
Merge pull request #1125 from Howaner/Entities

Add entity health saving.
BlockInfo is now a proper C++ singleton.

It is properly initialized before it is ever used.
Merge pull request #1126 from mc-server/BlockInfoInit

BlockInfo is now a proper C++ singleton.
Merge branch 'master' into Pickups
Fixed a comment and changed CombineCount to short.