Updated button support for HP Scanjet G4010

I got a Scanjet G4010 and the genesys backend doesn't quite match the button configuration of this machine:

I did a quick scan pushing the buttons and determined the GPIO bits.

One question though: this scanner has a "Scan Film" button which doesn't really fit any of the available options. I have assigned it in the patch to "Extra Switch" which seems a bit unhelpful. ☹

Would you have any objection to me adding a new category of Scan Film?