Files and folders that we create during backups, copy log, or MTP
operations often do not have the proper uid/gid/contexts assigned.
We will attempt to read the proper contexts from the settings
storage path and assign those same contexts to any files or dirs
that we create.
Change-Id: I769f9479854122b49b499de2175e6e2d026f8afd
create a framework for computing digests and reading digests in TWRP
add space for backwards compatibility with bb md5sum
Change-Id: Ia18e3f430eed5eba22e5052d39b9b8d88ecd4536