New upstream release.
Closes: #506150
(gscan2pdf: pdf creation failes when using LZW compression)
Closes: #512758 (Error handling: 'Unknown message: "scanimage: sane_read:
Operation was cancelled"')
Closes: #512760 (Error reporting: empty document feeder not reported)
Closes: #515605 (gscan2pdf: repeating save-dialog when saving as pnm)
Closes: #517913 (gscan2pdf: Tools -> Gimp broken)
New Depends: libset-intspan-perl, libforks-perl