Problem with WMTS TileMatrix-values in some viewers

Some viewers (like the Geocortex Silverlight Viewer and arcgis.com) won't show wmts-tilesets because of a discrepancy in the capabilities provided by mapcache. These viewers expect a TileMatrix-value in a TileMatrixSetLink to be the same as/correspond with the ows:Identifier-value for the TileMatrix in the TileMatrixSet.