Bug 939792 - Remove get_active_frame from keyboard app object and other app objects, make keyboard methods fall back to displayed_frame
Bug 929313 - [UITest] CSS dimension test
bug 925970

* Same visual refresh but, for commit against master.

r=amirn@e.me
Merge pull request #13443 from nullaus/awesome-bar-ui-master

bug 925970
Merge pull request #13936 from MBRSL/bug-929313-CSS

Bug 929313 - [UITest] CSS dimension test, r=gasolin
Merge pull request #13869 from zacc/bug_939792

Bug 939792 - Remove get_active_frame from keyboard app object and other ...
Bug 918303 - Quick advance through emails
Refactor WIP
Use MessageCursor instance directly in cards
Unit test the MessageCursor
Implement MessageCursor#onMessagesSpliceComplete
Only export a single MessageCursor
Initial scrolling implementation