Comment 7 for bug 43730

I've attached a patch that makes the export dialog report to the application status bar. If it hits an error, it'll be reported there too, so any old message should never stick around to confuse the user (if an old message indicates success, while the export fails). These are mostly copies from the error messages given by the dialog.

Batch exports reports how many files were successfully exported, out of how many. "Successfully exported 3 files from 4 selected items." (Tested by setting one path to have inkscape:export-filename=/dev/path.png, which itself fails.)