F2FS bullshitz

* Add code to analyze the fstab to determine whether we
are in f2fs mode or ext4 mode

* Add settings to enable/disable f2fs forcing mode so we can
switch on the fly. Force will force all wipe/format calls to
use f2fs or ext4 depending on the selection.

* Also added code to ensure settings are re-written back to
internal sd after a super wipe.  Also removed fstab code to
determine the mode since we now have a setting for it.