fix stat for correct free space when backup path is second storage

Change-Id: I762269d696a194889e74c101b9338920e924ebb5
Enable mount usb for external storage on datamedia devices

Change-Id: I73b4112983b7b118d738eb224b32f4f0beb5d147
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
If sd-ext is defined in recovery.fstab, but user did not partition sdcard, silent failure while formatting device (every nandroid restore or wipe data)

Change-Id: I3ee2f891899be8e4fe0d722e64357dc5e7bc7428