Feed.py could use an option to feed w/o waiting for a user to appear

[pwdirks]

Issue #218 added parsing of all standard config options and command line overrides to Feed.py. It's unclear what it would mean to use Feed.py without connecting to a (remote) wire but it might make sense to feed a signal locally, on the sounder or with audio. Without a wire to monitor, Feed.py would need an option to simply start feeding regardless of other connections.

It might make sense to set this option automatically if "--remote" is turned off.