Merge mozilla-central to fx-team
Bug 930641 - Remove the social.allowMultipleWorkers preference, r=mixedpuppy.
Bug 951260 - Social Status button icon stretched on retina screen, r=mixedpuppy.
Bug 950656 - The separator string between the headers name and value isn't shown, r=past
Bug 830344 - Part 1: Remove the lazy append mechanism in the variables view, r=past
Bug 830344 - Part 2: Implement pagination when expanding objects with lots of properties, r=past
Bug 951674 - Vertical splitter isn't shown for the Events tab, r=fitzgen
Bug 951694 - Sources pane can overlap content over the source editor, r=fitzgen
Bug 899276 - Don't collect/save private tabs. r=ttaubert
Bug 935417 - Better word wrapping in the css rule view. r=harth
Bug 948894 - Move inline scripts for about:apps into AboutApps.js. r=mleibovic
Bug 950667 - DevTools CSS - Use an attribute instead of .highlighted class for styling tabs like the paused debugger. r=bgrins
Bug 951118 - TypeError when null account is verified. r=ferjm
Bug 951518 - Added missing ending whitespace to help text. r=flod
Bug 951658 - Kill the inspector front even if walker.release() failed. r=pbrosset
Bug 946656 - Add debug output to ToolbarTitleTextChangeVerifier. r=margaret
Bug 883739 - Set the correct pref so test_update.js does not access services.a.m.o. r=Mossop
Bug 950873 - Switch Social.jsm to use asynchronous Promise.jsm. r=markh
Bug 951609 - Fix scope issues in child.js. r=ochameau
Backed out changeset eb4d2915ab26 (bug 951674)