unmount /data on user request for /data/media devices

Change-Id: I86723215edb8c5d256bdd380ff1806729aa81a8f
clean up reboot to main system and remove old useless variables

Change-Id: Idf8cda0639e3fa5e6073b196a85899c57ca18e9b
Merge "clean up reboot to main system and remove old useless variables" into cm-10.2
Merge "unmount /data on user request for /data/media devices" into cm-10.2
Merge branch 'cm-10.2' into martincz