Update game.cpp

Added sliding in levels
Update game.h

Added sliding
Heroes cant walk into enemies. Enemies can push the hero
Merged
Update image.cpp
Update image.h
Update color.h
Update color.h
Update color.cpp
Update util.h
Create collision.h
Create collision.cpp
*** Temporary, just for testing ***
*** Temporary, just for testing ***
Delete littlebigtest.cpp
Delete built-littlebig.sh
Merge branch 'engine' into macVersion

Conflicts:
	code/game.cpp