m7: send phone apps status to proximity sensor

Needs http://review.cyanogenmod.org/#/c/48997/

Change-Id: I457c40892a51d151a4682193e5c37c926f6cb2f4
m7-common: enable option to set button brightness 

Change-Id: I2aab2fec2a5fa8f6907242498c23029d77b2f81c
Merge "m7-common: enable option to set button brightness " into cm-10.2
Merge "m7: send phone apps status to proximity sensor" into cm-10.2
Merge branch 'cm-10.2' into martincz