Added color information to debug menu

Changed the debug screen to actually show meaningful brightness numbers,
including the 0xRGB color value of the current block
Fixed Chunk.getBlockLightValue

The huge numbers generated for block brightness were overwhelming the
sunlight, making getBlockLightValue return the block brightness even
when each component was only 1. This commit masks the values before
comparing to only compare the light component of each. In particular, rl
in the debug menu is actually accurate.
Merge pull request #23 from Murray65536/1.7.10

Added color information to debug menu