Brings performance settings up-to-date with cm-10.2

Includes the following cm-10.2 commits:
http://review.cyanogenmod.org/30667 Performance: BootReceiver: set CPU min/max freqs before CPU governor
http://review.cyanogenmod.org/31886 Adding configurability of frequency cap (min/max) files' path.
http://review.cyanogenmod.org/48007 Cleanup: remove useless checks.
http://review.cyanogenmod.org/51295 Cleanup performance settings strings

Change-Id: If94d02745606e9bdca92a89ea7129a44878226a2
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_packages_apps_Settings into cm-11.0

Merged changes from upstream