Bug 1057716 - d3d11: Properly copy the background. r=bas, a=sledru

Previously we were copying an empty box.
Bug 993885 - Refactor SendTabActivity to avoid a race condition. r=mcomella, a=sledru
Bug 1050780 - Avoid disabled items in GeckoMenu's adapter. r=margaret, a=sledru
Bug 891258 - Use Australis styling for the findbar buttons. r=Unfocused, a=sledru