improvements to lighting engine
midpoint displacement algo fixes + 2d terrain viewer
terrain generation improvements
added mountain range type
added type generator
new height map generator
support code for eventual chunks at a distance
terrain generator improvements
added map for debugging
implemented probabilistic grass growing
small changes to zombie spawn code
added hunger bar
terrain generator and zombie generator improvements
implemented zombie health + damage
bumped ver no.
Merge pull request #34 from es92/master

add lots of commits!