Fix issue where android device manager, etc, dont actually wipe data.

--wipe_data issues via /cache/recovery/command will now completely format data.

All other manual wipe commands will preserve data on /data/media.
There is another mounts/storage option that will do a true data format.

Change-Id: Ie8ecd2b0e14c3bb1d8a404ea868cdf703455d2ab
Merge branch 'cm-10.1' into martincz