Support f2fs format

This allows devices like Moto X, which have f2fs formated
data partition to be used with CWM recovery. Format data
works as enteded as well as backup/restore.

Change-Id: I8b56252cc462c9e9ff2824bc817ea00ddd4ccacc

Conflicts:
	extendedcommands.c
Add support to format as F2FS.

Change-Id: I05b97970990d47cd028c1d1899a3c98e7d3a6ab9