Merge pull request #5 from jshiraef/master

Entity and enemies
Refactored attributes up to the entity superclass.
Established an enum for orthogonal direction.
Tried to get the collision to work.
Cleaned up the main loop of the game.
Began refactoring the classes for the world.
Merge pull request #6 from arcym/master

Cleaned up the relationship between entity and world.
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".