Add _exit(...) function to pointFeature

Need to remove actor from render context.
Add clear(...) method to featureLayer

Method to remove all featured associated with the layer.
Add animation events
Add animation support to map

Add support for animating layer over a global time range.
Remove trailing whitespace
Add test for animation support
Prevent user event handlers from being remove

Rather than using off(...) move bind outside _animate()
Fix trigger call
Merge branch 'animation-support' of git://github.com/OpenGeoscience/geojs into animation-support

Conflicts:
	src/core/map.js