Add the option -mt/--mtime to pass a timestamp which is used as filedate
for the containing files.
So far, it isn't used for anything written to the extra fields,
therefore requires the -X (eXclude eXtra file attributes) parameter to
be effective.
Signed-off-by: Mathias Kresin <dev@kresin.me>
One image requires a zip compressed image, so add the zip util found in
the packages feed, and extend it with some useful debian patches.
Signed-off-by: Mathias Kresin <dev@kresin.me>