Policy: support for volume wake/music control

port from ics:
commit 153e40d29fae542b9c70f994d64e4c043645a523
Author: Sven Dawitz <sven@dawitz.de>
Date:   Sun Jan 8 21:32:43 2012 -0700

    add lockscreen volume button music control (framework part)

        *long-press vol up for next, vol down for previous
        *screen must be off to work
commit 7cee3218014293da1d131f3adfd0a53c1b23a473
Author: Andrew Sutherland <dr3wsuth3rland@gmail.com>
Date:   Fri Jan 13 22:03:51 2012 -0600

    volume button wake
commit 238568c72f140708d59db28ec520b15a35f12369
Author: Andrew Sutherland <dr3wsuth3rland@gmail.com>
Date:   Fri Apr 6 18:03:49 2012 -0500

    adjust vol wake / music control logic

    to allow concurrent operation (short press wakes / long press skips track)
    based on patch from <daneshm90@gmail.com>

Change-Id: Ic45a50df98dad5933102149017211f446ee46500

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

* adjusted for 4.2 api

Conflicts:
	core/java/android/provider/Settings.java
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java