Gui - assign video device, saved profiles

[sundoulos2]

I use droidcam for jitsi calls with multiple cameras. It works well but switching cameras in the call is a little temperamental. Two additions to droidcam-gui would be helpful:

1. a dropdown list of devices available for droidcam - e.g. v4l2:///dev/video2, v4l2:///dev/video3, v4l2:///dev/video4.
2. the ability to save a named profile containing settings including IP address and device assignment and provision to start the gui with a named profile.