cups-filters 2.0.0

Final 2.0.0 release with a last fix

• universal: Enable application/vnd.cups-postscript as input
  There are filters which produce this MIME type (such as hpps of HPLIP), and if someone uses such driver on a client and the server has an IPP Everywhere/driverless printer, the job fails (Pull request #534, requires libcupsfilters 2.0.0).