Add delta.ua - a binary to apply an upgrade of DELTA_FS type.

Add delta.ua - a binary to apply an upgrade of DELTA_FS type.

The binary is build with code previously from tota-ua and libtota, although some
changes were made. They include: changes to make delta.ua a command line tool
(reading given parameters instead of reading config files), changes to make delta.ua a tool
only applying the deltas and only applying them for one partition, adding support for handling
hardlinks (previously in cases where harlinks were present in a delta, upgrade wasn't guaranteed
to be successsful), removing code/files unused for update types other than DELTA_FS
and other more minor changes (e.g. removing unused functions)

Change-Id: Ice1e272a553abb5ebae4230eaffe82afc931b204