Adjustments for release.
Fixed a memory leak on world unload, should close #498.
Fixes a potential NPE in adapter if block driver returns null environment.
Merge branch 'OC1.3-MC1.6.4' of github.com:MightyPirates/OpenComputers

Conflicts:
	build.properties
Added helper for pulling from git
Merge branch 'master' of github.com:MightyPirates/OpenComputers into master-1.6.4