support converting between f2fs <-> ext4 format type

- fix restoring backup to f2fs partitions
- fix formatting extra storage to f2fs
6.42.2
f2fs: do not format whole /data when not expected on /data/media devices
jflte: enable f2fs support in recovery
6.42.3
f2fs: allow /data f2fs/ext4 migration on non /data/media devices
6.42.4
f2fs: recreate /etc/fstab after ext4/f2fs conversion
this fixes use of system mount command
remove dead code
6.42.5
default to busybox tar:
- use busybox tar by default as it now supports selinux context backup/restore
- unify libtar and busybox tar options (-p for selinux context)
- remove now deprecated external selinux container code
6.42.7
revert to using libtar for nandroid operations
optional debug code: backup /data selinux context to external container
6.42.9
nandroid backup: fix 'media' exception:

In CWM, a bug present from the begining was preventing any path/file named media from backup on /data/media devices
This fix will only exclude /data/media path and not other media files/folders
6.43.0
cleanup function to preserve /data/media
fix f2fs conversion of /data on /data/media devices
cleanup useless code:

reset_ext4fs_info() is always called by make_ext4fs()