perf: optimize binding equals performance. The angular watch function is already fetching the scope value, so there is no need to fetch it again inside equals. Also the symantics of `angular.equals()` is such that filtering the properties with `$firebaseUtils.scopeData()` before passing to `angular.equals()` is unnecessary.
perf: optimize binding equals performance.
The angular watch function is already fetching the scope value, so there is no need to fetch it again inside equals.
Also the symantics of `angular.equals()` is such that filtering the properties with `$firebaseUtils.scopeData()` before passing to `angular.equals()` is unnecessary.

cesarmarinhorj/angularfire,cesarmarinhorj/angularfire,douglascorrea/angularfire,yoda-yoda/angularfire,FirebaseExtended/angularfire,nbr1ninrsan2/angularfire,fbentz/angularfire,itxd/angularfire,douglascorrea/angularfire,jamestalmage/angularfire,bpietravalle/angularfire,denisKaranja/angularfire,FirebaseExtended/angularfire,fbentz/angularfire,douglascorrea/angularfire,yoda-yoda/angularfire,bpietravalle/angularfire,itxd/angularfire,fbentz/angularfire,cesarmarinhorj/angularfire,FirebaseExtended/angularfire,nbr1ninrsan2/angularfire,yoda-yoda/angularfire,denisKaranja/angularfire,jamestalmage/angularfire,bpietravalle/angularfire,jamestalmage/angularfire,nbr1ninrsan2/angularfire,denisKaranja/angularfire,itxd/angularfire