working on dungeon movement. 
surrounded image loading with try/catch
wall collision and smooth scrolling added.
the collision and was added by loading all Tile properties in an array
via loadroom(). the scrolling was added through setPosition() which is
called everytime the hero collides with a "door".
began work on collision for entities.
Merge pull request #7 from jshiraef/master

Wall collision and scrolling through map