fixing bug #447315

[Joop Stakenborg <pg4i@xs4all.nl>]

#447315 talks about: "/usr/bin/listen (and related manpage) is available
in listen package too and an error is raised when both are installed".

listen is a binary from the popular listen package, a music player
and manager for GNOME.

We could ask the upstream listen to change their binary name,
but I guess it would be less effort if we change ours, the name is
a little obvious... What about ax25listen? This is in line with
most of the binary names in the ax25-apps package.

I would also vote for renaming call to ax25call.

Any ideas, suggestons?

Joop, PG4I