Changes

Updated submodule.
Submodule src/main/xproc 7bf9f01..baca342:
 > Removed column Druckort from testimony table.
 > Documentation
 > Sigil links in testimony metadata
 > Druckort
 > Dokumenttyp => Beschreibung auch in Metadaten
 > Metadata fields re. date
 > Ignore some testimony metadata fields
 > Normalize characters in testimonies.
 > Updated bibliography
 (commit: 3ca95e9)