added option to delete a saved filterset.
added owner to the unique constraint in the tabel for saved filters:
combination of owner, name and nr should be unique.
prevent addition of duplicate rules when loading filterset.
several layout improvements and  of matrix datamodelchanges to
shared/matrix.xml in stead of animaldb.xml.
new icons for layout improvements to filter. (partly also in
molgenis-legacy project!!).