Bug#877024: modemmanager should ask before messing with serial ports

[Ian Jackson <ijackson@chiark.greenend.org.uk>]

Keith Packard writes ("Re: Bug#877024: modemmanager should ask before messing with serial ports"):
> Yeah, I was just thinking that it would be easier to stop installing
> support for modems by default than to actually fix modemmanager to
> behave itself. It's certainly how I work -- apt remove modemmanager
> solves a world of problems for me.

But I should be able to use the same laptop to (1) control my machine
tools or talk to my rpi or whatever (2) go online with a usb mobile
modem when I'm out of the house.  Possibly even simultaneously.

And, people shouldn't have to install support software to get their
internet to work.

Ian.