Quiet Hours: Clean up and consolidate code

- Added: Allow disabling of system sounds

Ported from cm-10.2.

Change-Id: I7d2619becb99c336d23896a672136f491d972abd
Fix "no recent apps" color

RIP #33b5e5

Change-Id: Iae5948e224d06023962e43f905756017b42f0637
Merge "Fix "no recent apps" color" into cm-11.0
Port Forward Quick Unlock

PS3: Fix whitespace and author.

Change-Id: Ic64c47bb35ee4da13b0332d853725a6ef60ac8d4
Merge "Port Forward Quick Unlock" into cm-11.0
Merge "Quiet Hours: Clean up and consolidate code" into cm-11.0