Rename _getKey to $$getKey
Merge pull request #457 from firebase/kato-extendFactory

Simplified $$updated method in $FirebaseObject
Replace references to .name() with .key()
Grammar
Merge pull request #458 from firebase/kato-extendArrayFactory

Simplify $extendFactory for $FirebaseArray
Merge pull request #462 from firebase/kato-_getKey

Rename _getKey to $$getKey
Merge branch 'master' into kato-indexfor

Conflicts:
	src/FirebaseArray.js