[2/2] Forward port power connect/disconnect notification support

Original commit info:

    [2/2] Power connect/disconnect notification support

    part 1/2: frameworks/base PowerUI and Settings
    http://review.cyanogenmod.org/#/c/35241/

    part 2/2: packages/apps/Settings Sound settings
    http://review.cyanogenmod.org/#/c/35242/

    Change-Id: I7ddd8a47ae4f9a62c586023d151ac42bbe8424c7

    Power sound notifications: fix ringtone picker title

    Change-Id: Ied0a08ec1607b778324e69a7b40bac056235bebf

    Settings: Rename 'Power sounds' to 'Charging sounds' and add summary

    Change-Id: I1cb872917e2d03f0a1c77c25c27f2a0496f9bc05

Change-Id: Ibde52fcd6fd0fabc9eeefc7e6f5a3971527285d7
(cherry picked from commit fda90f03ba1e619a8b02ffe11145e55670f57c4d)
Performance profiles

This changes adds support for custom performance profiles through overlays. Supported
devices should define config_perf_profile_prop with the proper system property to be set
and fill an init.rc file with the appropiate handlers for every defined performance profile..
Patchset 2: Rebased
            New simplified strings
Patchset 3: Fix build
Patchset 4: Rebased

Change-Id: I5a6612db94da3c09d8ec2e8920bf9516f62d0024
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
(cherry picked from commit 9ddc513445e73a446d27ade6522aa5f7b334c4d6)

Conflicts:
	res/values/config.xml