Multi-remote/Multi-CommandSet exports

[bengtmartensson]

There should be a possibility to create multi-remote exports, at least in Girr format, possibly also in Lirc, Pronto Classic, C, etc.

At least in a first version, it makes sense only to invoke from the Import pane, i.e. if we already have multiple remotes.

Also multiple CommandSets (in the sense of Girr) should be supported.

Cf. #52

[bengtmartensson]

Also:

• Replace the silly inquire data (device manufacturer and such)
• New column: display name