Comment 2 for bug 1174891

I found that if I use the shotwell way to detect camera it fixes the get_camera_model():
   metadata.get_tag_interpreted_string("Exif.Image.Model")
I will check today if it will compile after I make the changes for the other method calls.

Users of elementary always have shotwell installed I think, but I'm not sure if they use the shotwell repository, have to check when I'm on the elementary machine.