Revision 387213

Certain filter combinations in PDF could lead to invalid PDFs. DecodeParams were not properly handled.
Default filter for XMP metadata set to NullFilter as XMP metadata should always be embedded as clear-text so non-PDF-aware XMP processors can extract the metadata.
Default filter for DCT/JPEG- and CCITT/TIFF-encoded images set to NullFilter because these two compression methods already do a good job. An additional flate filter (as was applied before due to the single default) helps a just little but also adds processing time. If anyone wants to squeeze every possible bit out of the PDF you can use the following in the user configuration:
      <filterList type="tiff">
        <value>flate</value>
      </filterList>
      <filterList type="jpeg">
        <value>flate</value>
      </filterList>