Bug 887586 - Replace referece to current accessible in VisualPresenter with a WeakMap. r=davidb

This patch does other things to:
1. Refactor out getBounds()
2. Fix a mistake in PivotContext._isDefunct()
Bug 887592 - Fix filtering on browser events. r=davidb
Bug 775459 - Make APZC attachable only to container layers. r=kats

--HG--
extra : rebase_source : 5a94d9958013f92e64db4781e09bdc9db4b66c9a
Bug 775459 - Implement hit testing on layer tree + tests. r=kats

--HG--
extra : rebase_source : c596cc4c4dd9810319830ec8105a5e251e9b0ddb
Bug 888749 - Don't be confused by <children> elements. r=dao
Bug 889451 - Implement range analysis for or, xor, not, ursh, abs, min, and max, and better range analysis for shifts and mul. r=nbp
Bug 838402 - Add new identity mode for mixed active content.  Change messages for following modes: encrypted, mixed content, mixed active content, and mixed active content blocked with display content. r=dolske
Bug 838402 - update a test case with the new identity mode for mixed display content. r=dolske
Bug 888280 - Give several things in CTypes.cpp internal name linkage. r=evilpies
Bug 888280 - Move Loop out of LICM.h and into LICM.cpp r=evilpies
Bug 889554 - Save session between app upgrades. r=mfinkle
Back out cd6b4a1ef09c (bug 886988) for mochitest failures on a CLOSED TREE

--HG--
extra : amend_source : d9bada346fa6179452d28a49633badef0de79e47
Bug 888497 - Fix focus order of browser toolbar. r=sriram