Fixed audio output device (PA) selection.
Fix the "back to default" case.
Tabulate and simplify receiver::set_demod()
Merge pull request #62 from nhasan/master

Allow using audio output device other than the default one.
Updated.
Merge branch 'master' of https://github.com/csete/gqrx

Conflicts:
	applications/gqrx/receiver.cpp