fix(database): Add $ref to observables#447

Merged

davideast merged 3 commits intoangular:masterfrom katowulf:kato-294-addref

Sep 19, 2016

+109-30

Commits on Aug 17, 2016

feat(FirebaseObjectObservable, FirebaseArrayObservable): Add $ref to observables
katowulf
committed

Commits on Aug 24, 2016

Locked zone.js to 0.6.12 per bug angular/zone.js#404 , bug angular#468 created to address this.
katowulf
committed

Commits on Sep 19, 2016

Fix merge conflicts
katowulf
committed