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: I10999b100d3c41ae749f9cba270b0a94d3e8385d
Recovery: remove unnecessary BoardConfig parameters

BOARD_SUPPRESS_EMMC_WIPE: according to http://review.cyanogenmod.org/17326 ,
this is only relevant to Samsung devices with buggy firmware

BOARD_VOLD_EMMC_SHARES_DEV_MAJOR: already defined in the # Vold section

BOARD_USES_MMCUTIL: cannot find source that utilizes this

Change-Id: I3bc5417e27bbd326b36f63be6384a24b25b70a5b
Recovery: support building TWRP

Change-Id: I71ac88bf67b52d9c6ca1406b0795a1d32c31b35f