Add sprite example to Crafty.loader
Fix text rotation with canvas

The text entity was directly using it's x/y coordinates to draw on the canvas.  To account for rotation, it needs to use the coordinates passed by the draw event.
Merge pull request #750 from mucaho/loader_docs

Add sprite example to Crafty.loader
Merge pull request #756 from starwed/text-rotation-fix

Fix text rotation with canvas
Now .delay method can receive a 'callbackOff' argument for when the delay iterations end.

Also, delay component gains a .cancelDelay method.
Merge pull request #759 from heniotierra/delay_modified

Improved Delay component