engine/canvas - change canvas size from 512x480 to 250x400
engine/draw - wrap bliting with a begin/end instead of begin/end done in engine/room
engine/texturable + texturePool - callback for image onLoad happens instantly if the image has already been loaded
engine: entities stored with depth information for rendering with a pseudo z-axis
examples/flappy_bird_clone: major art revamp
Merge pull request #2 from tomcraven/feature_art

Feature art