* fix issue with LocalChunkProvider where multiple chunks are generated for the same chunk position
+ improved fix for LocalChunkProvider
* further improvement of the bugfix for LocalChunkProvider
+ added log messages to indicate redundant chunk generation
Merge pull request #437 from mbrotz/bugfixes

Important issue with LocalChunkProvider
Merge branch 'develop' into stackable-chunks

Conflicts:
	src/main/java/org/terasology/world/chunks/provider/LocalChunkProvider.java