docs(EventHandler): Add EventHandler documentation.

Add documentation to EventHandler. This change also makes fields and methods within EventHandler, which are not intended for public use, private.

Closes #764
fix(component): revert regression of injecting Element/Node into Component
feat(filters): revert filter being restricted to top level

See: 5bcea6492f6d0fd39ba316fa3b241c50bb94de8d
feat(doc): Library description for angular.animate
feat(doc): Animation library documentation updates and fixes.

Closes #760