Added health potions to the world
Added max-hp.

Potions cannot heal past max hp now and level up increases max hp rather
than healing player
Forgot to change apply-fn to poison for skeleton
Added max hp to monsters, and added a forest level
Merged to Master
Fixed bug
Now darkening destr entities when damaged.
Merge branch 'master' into maze-gen

Conflicts:
	desktop/src-common/rouje_like/config.clj
	desktop/src-common/rouje_like/world.clj