Mainly because we need somewhere to stash the call end regex, and
it's silly to have a 3rd instance of that in MMPortSerialAt when
we already have one in the serial parsers that MMPortSerialAt
relies on pretty heavily.
Signed-off-by: Dan Williams <dan@ioncontrol.co>
We are going to allow including the plugin sources built within the
ModemManager daemon binary; moving the sources within the daemon
sources directory makes it easier.