Levels are now only saved when a change is made
Undo data now saves in flatfile correctly
Player connections are now only closed once.
Updated gitignore
Merged upstream changes
Basic fixes
Physics Improvements
Merge remote-tracking branch 'upstream/master' into Block-Tracking

Conflicts:
	src/net/mcforge/world/model/ClassicLevel.java
Undo data now compressed + more stuff added
* Added debug mode
* Added 3 new serialize options
* PhysicsBlocks no longer save _level variable
* Server now stops when cant bind to port
Merge pull request #25 from MCForge/Block-Tracking

Block tracking