Bug 905173 - PIN code screen should not display '3 tries left.' when loading

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- Changed tag to hidden
- Added tests
Bug 905208 - Implemented the banner when a new message of a thread arrive r=julien
Bug 925348: Spread out contact scroll rendering work.

This commit avoids spikes of DOM modifications during scrolling by tweaking
the tag_visibility_monitor parameters.  The new parameters result in more
frequent updates from the monitor which spreads the resulting work out
over time during scrolling.
Bug 924233: Add missing requires to comms unit tests.
Merge pull request #11997 from caiolima/bug-905208

Bug 905208 - Implemented the banner when a new message of a thread arrive
Revert "Merge pull request #12267 from pivanov/bug-908241"

This reverts commit 400d5fec2f099397575ded3ef8544150a9b472c5, reversing
changes made to a894561828a3a00ea54fe69fad26f0cadf6239fa.
Bug 924233: Add missing requires to homescreen tests.
Merge pull request #12818 from wanderview/homescreen-test-require

Bug 924233: Add missing requires to homescreen tests. r=crdlc
Bug 924233: Add missing requires to video tests.
Merge pull request #12817 from wanderview/comms-test-require

Bug 924233: Add missing requires to comms unit tests.  r=arcturus
Bug 919931 - After hanging up a phone call, the time on status bar disappears r=alive
Bug 926403 - Bump gaiatest version to 0.17. r=dhunt
Bug 925164 - Remove role and label from slider area.
Merge pull request #12766 from eeejay/bug-925164

Bug 925164 - Remove role and label from slider area.
Merge pull request #12758 from fcampo/retryCount-905173

Bug 905173 - PIN code screen should not display '3 tries left.' when loading (r=Rik)
Merge pull request #12778 from wanderview/contacts-render-jank

Bug 925348: Spread out contact scroll rendering work. r=arcturus
Merge pull request #12819 from wanderview/video-test-require

Bug 924233: Add missing requires to video tests.  r=djf