Bug 950800 - Add hardware composer setting

Now you can toggle the hardware composer on/off at any point without
restarting B2G.
Bug 942726 - Activate APZ for all Gaia apps for non-user build. r=alive
Bug 952466 - [Window Management] Improve app window and dialogs jsdoc
Merge pull request #14886 from vingtetun/bug942726

Bug 942726 - Activate APZ for all Gaia apps for non-user build. r=alive
Revert "Merge pull request #14659 from gasolin/issue-950080"

This reverts commit 5028d298c3be4effa75147703b3148883982038e, reversing
changes made to 0ef52554acf8cc115e40a95b2eab0117df3dff45.
Merge pull request #14905 from gaye/bug-952553

Revert "Merge pull request #14659 from gasolin/issue-950080"
Merge pull request #14903 from cctuan/952497

Bug 952497 - getPid in the rewritten install-gaia.js writes to a constant file name
Bug 918303 - Quick advance through emails
Merge pull request #13297 from gaye/bug-918303

Bug 918303 - Quick advance through emails
Merge pull request #14721 from dwilsoncaf/bug-950800

Bug 950800 - Add hardware composer setting, r=kaze
Bug 951932: don't allow pick from Music for ringtones
Merge pull request #14909 from davidflanagan/bug951932

Bug 951932: don't allow pick from Music for ringtones r=dmarcos
Bug 952225 - [Messages][Drafts] Support subject line in message drafts r=julienw

https://bugzilla.mozilla.org/show_bug.cgi?id=952225
Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Bug 951339 - [Messages][Drafts] Existing thread drafts not properly populated when a new message is sent to that same recipient r=julienw

https://bugzilla.mozilla.org/show_bug.cgi?id=951339
Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Bug 951450 - Flashing customizations currently fails with exception. r=yurenju
Merge pull request #14866 from acperez/bug-951450

Bug 951450 - Flashing customizations currently fails with exception. r=yurenju
Merge pull request #14899 from gasolin/issue-952466

Bug 952466 - [Window Management] Improve app window and dialogs jsdoc, r=alive
Bug 952611 - Disable broken gaia integration tests
Merge pull request #14908 from gaye/bug-952611

Bug 952611 - Disable broken gaia integration tests
Disable keypad test since failing on TBPL