Added paralysis, by adding energy system.

Currently only ticks entities if the player’s energy is <= 1, meaning
if the player gets extra energy, it will be able to move freely for
some amount of moves.
Added Bisasam_20x20.png for tree graphics
Merge remote-tracking branch 'origin/status-effects'
Maze-walls are are an entity, and take 2 hits to destroy.
Merge branch 'master' of https://github.com/dunjeon-masters/dunjeon-crawler

Conflicts:
	desktop/src-common/rouje_like/player.clj
Walls are now also a destructible entitiy.
Commented in rendering:220 about how/where to grey out tiles as they get damaged.
Things can now properly deal 0 damage and apply status effects.
Merged to Master