Sync ssot

Placeholder, needs more tests and comments. 
Fixes #1919 #1814 #2057 #2191 #2177 #2125 #2100 #1848 #1790 #1532 #1389 #1308

`Ember.RSVP.Promise.resolve(null)` or shorthand `Promise.resolve(null)`  (i wont to deprecate `RSVP.resolve` for ember 2.0