Bug 834530 - Make the TonePlayer handle the channel sounds will be played on r=drs

(cherry picked from commit 20a56c3cf6ea6b730d05d7a8cfa06e178cd5717c)

Conflicts:
	apps/callscreen/js/index.js
	apps/communications/dialer/js/dialer.js
	apps/communications/dialer/test/unit/tone_player_test.js
	apps/emergency-call/js/dialer.js
	apps/emergency-call/js/keypad.js
	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