Bug 924846 - [Keyboard][V1.2] Selected keyboard cannot be displayed while switching the keyboard between built-in keyboard and third party keyboard
Bug 929059 - Update pdf.js to version 0.8.629.
Bug 926871 - Prevent reflowing when the software button is hidden
[Bug 914591] make sure sessions get re-inited after expiration [r=ranbena]
Bug 929840 - [Settings] Use CSS for fake select elements
Bug916183 - Fix of Done button target is off
Bug 930417 - (Cost Control) Typo in short name for December

Should be DEC, not DEV. Affecting also 1.2
bug 930469, malformed properties file.
Remove leftover merge conflict marker
Bug 921685: Read device geometry info from cookie to avoid sync reflows.
Bug 930693: Fix checkbox select in export search mode. +shepherd
Bug 917344 - [Dialer] Turn off speaker if bluetooth headphone is connected during a call
Bug 917732 - [Keyboard] Candidate panel displays wrong data when clicking candidate-panel-toggle-button and space key at the same time
Bug 927783 -  [Messaging][Forward] Per message context menu opens options/action menu (to incl. delete, forward) r=schung,rwldrn
Bug 920261 - fix mailto links r=jrburke
Bug 931054 - [Camera] filmstrip.js access undefined preview metadata
Merge pull request #13097 from dmarcos/bug928614

Bug 931054 - [Camera] filmstrip.js access undefined preview metadata
Merge pull request #13002 from cctuan/926871

Bug 926871 - Prevent reflowing when the software button is hidden and add test cases for software button manager
Merge pull request #12992 from gaye/bug-920261

Bug 920261 - mailto links broken r=jrburke
Bug 912010 - [Keyboard][V1.2] Default Keyboard when all keyboards are de-selected - r=rlu r=garychen r=arthurcc

- Refactors `KeyboardHelper`
  - Renames the application method to `getApps`, which now caches response until the apps change
  - Adds a new API `getLayouts` to get a callback with an array of layouts.
  - Adds a new API `watchLayouts` to get a callback whenever layout settings or apps change
  - No longer calls `saveToSettings` itself when changing layout parameters.  This allows a consumer to batch operations before saving.
  - New method `checkDefaults` will make sure there is at least one `text` `url` and `number` keyboard enabled, calling the callback with anything it enabled.
  - +unit test suite.

- ManifestHelper now automatically returns a ManifestHelper for each object it contains
  - +unit test suite
  - now waits until access time to handle the language selection instead of creation time
     - this allows holding the one manifest helper and having its "name" property change with the language

- Settings Changes
  - Now uses `watchLayouts` from keyboard_helper
  - Now calls `checkDefaults` when disabling a keyboard
    - If a default is enabled opens a DefaultKeyboardEnabledDialog
  - Removed a bunch of commented out code for dealing with the old layout settings

- System Changes
  - Now uses `watchLayouts` from keyboard_helper
  - Will call `checkDefaults` whenever it can't find a keyboard to show, showing the default from `text` if it still can't find one

- Test suite
  - Moved some mocks to shared and updated require statements
  - Mock Settings now allows a "sync mode" that can call the callbacks for observers on demand.

Closes gh-12866
Revert "Merge pull request #13097 from dmarcos/bug928614"

This reverts commit 4c652c5ca43f301217cbabf8f781b93a860bec37, reversing
changes made to afbf45f26a73b7cd5e0a831bea48087331975286.