"Import Photos" error handling when import destination is read-only or device if
full could be improved (possible data loss, see below):

1) try importing to a read-only folder (or when device is full)
2) import progresses normally... (no errors, but also no information about the
problem)
3) import is completed but photos are not there (?)
4) repeat 1-3 ad infinitum until you realize what the actual problem was 

(the whole time i thought it was my camera or the libgphoto to blame)

*** IMPORTANT: If "Import Phtos" is used with "Delete images from Camera" then
this could possibly lead to permanent data loss: images are "imported" (though
not written) and then deleted from camera. In the end, then they are missing at
both locations! (unconfirmed, since the "delete from camera function does not
seem to work on my canon G2 - thank goodness!)