Bug 936369 - [system] Intermittent Travis Unit Test Failure: KeyboardManager Transitions Call showKeyboard against visible keyboard: Error: timeout of 2000ms exceeded r=janjongboom

LOOK MA NO INTERMITTENT!
Merge pull request #14756 from julienw/936369-fix-keyboard-manager

Bug 936369 - [system] Intermittent Travis Unit Test Failure: KeyboardMan...
Bug 918303 - Quick advance through emails
Move all messagesSlice work for message_list and message_reader into header_cursor
Bug 918303 - next/previous review followup
Just set message suid if load from cache, since slice not loaded yet