Added evented module; made ABM.Animator emit step and draw events
Added evented to gulpfile
Model also emits 'draw' event
Changed build order
No more evented animator
Animator now calls the _step function of a model
ABM.Model now mixes in ABM.Evented instead of subclassing
Merge branch 'upstream-master' into evented

Conflicts:
	src/model.coffee
Renamed ABM.Evented to Evented
u.mixin moves proto props to proto and own props to the destination object
Added Evented to global ABM
Update evented comment
Rename _step to stepAndEmit; add setupAndEmit
Update spriteSheets reference
Add evented tests to life.html
Merge branch 'upstream-master' into evented

Conflicts:
	src/model.coffee
Merge pull request #63 from backspaces/evented

Added evented module; made Model emit step and draw events; added tests in life.html