UI port select on start

[rexim]

When the application is started the user is presented with a UI list of available input and output devices to choose from.

This feature should supersede the device configuration from CLI.

Pieces

• Configuration #68 Configuration
• Implement Port Selection State #191 Implement Port Selection State
• Implement state switcher and incorporte Port Selection State in it #190 Implement state switcher and incorporte Port Selection State in it
• Replace state mechanism with screens mechanism #205 Replace state mechanism with screens mechanism
• Implement Port Selection State. #226 Port selection Screen