releasetools: Fix error text in ota_from_target_files

property isn't the variable name, prop is

Change-Id: I0fc6adddfd51ba9bc79f6559c61cd831203c9e3d
img_from_target_files: Create md5 hashes for each file

Generate an md5sum-fastboot.md5 file that contains an md5 hash of each
file in the fastboot zip and store the file in the zip.

Change-Id: I19c2ac5a84fb21e965953d1dad0ebcbfd0b78d47
Merge branch 'cm-11.0' into stable/cm-11.0

Change-Id: Ifd195ae8a0d6ab5e6408fdf48c4c097d4e09028f