Implemented a watchdog for issue #534.
Merge pull request #540 from mbrotz/bugfixes

Implemented a watchdog for issue #534.
Add placeholdery Light & Shadow module. Also include two missing dirs in module dirs and tweak the applet jar lineup
Whoops, missed a spot. Copy paste never fails!
Merge branch 'develop' of https://github.com/MovingBlocks/Terasology into stackable-chunks-2
Some work on mod data extensions.

+ Added class TeraNullArray
+ Added support for mod data extensions in class Chunk