Bug 1093951 - Entering wifi power save mode when screen off. r=alive

While screen is off, wifi would go to power save mode only
when wifi lock is held. If wifi lock is not held, wifi would
stay on and be turned off after |wifi.screen_off_timeout|.
We can more aggressively request the wifi driver to enter
power save mode before timed out. This is what the patch
intends to do.
Bug 1083528 - Add dev/stage Marketplaces to 2.0
Merge pull request #26091 from elefant/dev/bug1093951-wifi-powersave

Bug 1093951 - Entering wifi power save mode when screen off. a=bajaj
Merge pull request #26129 from crh0716/1098684

Bug 1098684 - Hide the AP PIN item r=eragonj
Bug 1059650 - [Browser]Back button stops working after clicking '+' icon multiple times

* Doesn't rely on 'mousedown' event to get the tab ID, use 'tap' event to select tab ID directly
Merge pull request #26206 from clouserw/1083528.2

Bug 1083528 - Add dev/stage Marketplaces to 2.0  r=fabrice
Merge pull request #26228 from begeeben/1059650_back_button_stops

Bug 1059650 - [Browser]Back button stops working after clicking '+' icon multiple times, r=Dale Harvey
Revert "Bug 1059650 - [Browser]Back button stops working after clicking '+' icon multiple times"

This reverts commit e5b514a212b49013b7c18f31b7a7696a07cde13a.
Bug 834530 - Make the TonePlayer handle the channel sounds will be played on r=drs

(cherry picked from commit 20a56c3cf6ea6b730d05d7a8cfa06e178cd5717c)

Conflicts:
        apps/callscreen/js/calls_handler.js
        apps/callscreen/js/index.js
        apps/callscreen/test/unit/calls_handler_test.js
        apps/communications/dialer/js/dialer.js
        apps/communications/dialer/js/dialer.js
        apps/communications/dialer/test/unit/keypad_test.js
        apps/communications/dialer/test/unit/tone_player_test.js
        apps/emergency-call/index.html
        apps/emergency-call/js/dialer.js
        apps/emergency-call/js/keypad.js
        apps/emergency-call/manifest.webapp
        apps/emergency-call/test/unit/keypad_test.js
        apps/sharedtest/test/unit/dialer/telephony_messages_test.js
        build/jshint/xfail.list
        shared/js/dialer/keypad.js
        shared/js/dialer/telephony_messages.js
        shared/js/dialer/tone_player.js
        shared/test/unit/mocks/dialer/mock_calls_handler.js
        shared/test/unit/mocks/mock_audio.js
Bug 1092362 - Use the default audio channel when playing audible tones outside of calls r=drs,francisco

(cherry picked from commit e327daf01fac1e5fbe2ba732c26e3a21db32443a)