Bug 968709 - Allow system app to listen to bluetooth-pairing-request.
Bug 881469 - [Messages] Implement Navigation object r=azasypkin,schung

This commit implements a Navigation abstraction to handle navigating between
panels. It also introduces the concept of panels.

Each panel can have 4 lifecycle methods: beforeEnter, afterEnter, beforeLeave,
beforeEnter. These methods either return nothing or a promise.
Merge pull request #18524 from JaminLiu/BT_pair_marionette

Bug 968709 - Allow system app to listen to bluetooth-pairing-request. r=echou
Bug 950673 - Delay animationend event until active app loaded.
Use v0.3.5 marionette-apps
stability check
Stability check for js marionette tests.