Backout changesets 37f9a5424227, c1578a4fc86d and a417424f9213 (for bugs 933354, 929021 and 923193 respectively) while we figure out performance regressions

--HG--
extra : rebase_source : e4a004a15c92b5a8a8b780e7da779ac86d1c29be
Bug 936628: Add media query to check for whether we have a color picker backend available. r=jimm
Bug 907463. Ignore result of very big canvas reftest. r=roc DONTBUILD
Bug 897023 - [OS.File] Be smarter with functions that can fail with becauseAbsent/becauseExists. r=Yoric
Bug 900415 - Should be able to open the autocompletion popup at an offset from the anchor node. r=msucan
Bug 649002 - Use XPCOMUtils.defineLazyModuleGetter in places.js. r=dao
Bug 891110 - Detecting attempts to pass undefined in declareFFI. r=Yoric
Backed out changeset 3232989e79e7 (bug 897023) for mochitest-other failures.
Bug 935526 - Remove redudant uses of 'this' in PageActionLayout (r=wesj)
Bug 935543 - Remove unused members in BrowserToolbar (r=wesj)
Bug 892275 - F2 should make the selected node and its children editable as html; r=mratcliffe
Bug 928050 - Specify whether to iterate over atoms zone (r=bhackett)
Bug 853423 - Block speculative connections for local IP addresses r=mcmanus
Bug 853423 - Tests to verify speculative connection are blocked for local IP addresses r=mcmanus
Backout changesets 238b3c81f42c and rest of a417424f9213 (bug 928798 and rest of bug 923193 respectively)

--HG--
extra : rebase_source : a453412840da1eacb9d5c6f9f553137efa050e0c
Bug 818287 Remove data URL prefix from screenshots. r=dhunt
Merge mozilla-central and inbound
Bug 894914 - Disable test_postMessage_closed.html on Android & B2G due to intermittent failures.
Bug 915350 - Disable testBookmark due to intermittent failures.
Bug 936927 - Build the HTML parser in unified mode; r=hsivonen