Bug 1065511 - guard against falsey unfilteredStack. r=etienne

* Fallback to using StackManager.getCurrent() in exitToApp
Bug 1073159 - [System] fix update_manager.js tests with a newer mocha r=etienne
Bug 1072797 - Use app's manifest.webapp for shared import pages
Bug 1052136 - Clean up mozL10n API use in Communications, part 3, contacts commons
Bug 1052136 - Clean up mozL10n API use in Communications, part 4, views
Bug 971541 - [System2] Instantiable QuickSettings r=alive
Merge pull request #23967 from sfoster/task-manager-bug-1065511

Bug 1065511 - guard against falsey unfilteredStack. r=etienne
Bug 1073534 - Add "cancel" string to dialer. r=Rik
Merge pull request #24306 from KevinGrandon/bug_971541_systemv2_quick_settings

Bug 971541 - [System2] Instantiable QuickSettings
bug 1069452 - Never take screenshot of closing AppWindow if part of homescreen. r=alive,etienne
Bug 1052136 - Clean up mozL10n API use in Communications, part 2, dialer
Merge pull request #24396 from zbraniecki/1052136-clean-up-mozl10n-api-in-communications-dialer

Bug 1052136 - Clean up mozL10n API use in Communications, part 2, dialer. r=drs
Merge pull request #24398 from zbraniecki/1052136-clean-up-mozl10n-api-in-communications-contacts-common

Bug 1052136 - Clean up mozL10n API use in Communications, part 3, contacts commons. r=jmcf
Merge pull request #24237 from zbraniecki/1052136-clean-up-mozl10n-api-in-communications-views

1052136 clean up mozl10n api in communications views. r=jmcf
Merge pull request #24451 from zbraniecki/1072797-use-apps-manifest-for-shared-pages-import

Bug 1072797 - Use app's manifest.webapp for shared import pages. r=stas
Merge pull request #24481 from DouglasSherk/1073534-callscreen-cancel

Bug 1073534 - Add "cancel" string to dialer. r=Rik
Bug 1052136 - follow up fix to a unit test that regressed. r=me
Merge pull request #24447 from julienw/1073159-fix-update-manager-tests

Bug 1073159 - [System] fix update_manager.js tests with a newer mocha r=...
Bug 1071727 - [Gallery] - Fix for gallery pick activity while USB is plugged and than disconnected r=djf
Merge pull request #24488 from punamdahiya/Bug1071727

Bug 1071727 - [Gallery] - Fix for gallery pick activity while USB is plugged and than disconnected r=djf