jewel: support building recovery

To be used in conjunction with recovery files provided by s4-common

CWM and TWRP: leaves 16kb footer at the end of /data to store
encryption information (if needed).

TWRP: supports backup and restore of encrypted /data partition
and includes USB OTG as a storage option.

Change-Id: I112e9412cb3df67a435c833efc05704132444d8a
encryption: needed changes to allow encryption of data partition

1) cryptfs.c requires fstab be named fstab.${ro.hardware}
2) include encyptable parameter on /data in fstab
3) formatting /data in recovery leaves 16kb trailing
4) make fstab.qcom available to recovery

Change-Id: I7e577bdf3e28d0d727f9e083f9a90a5420c0db2c
Merge remote-tracking branch 'upstream/cm-10.1' into cm-10.1