GetFeatureInfo support for remotewmts backends

Adds support for GetFeatureInfo when remote WMTS backends are used (eg. in a remotewmts-tilestore). Also supports replacing parameters in remotewmts-tilestore. See also http://tracker.deegree.org/deegree-services/ticket/501

Selects the first GML info format supported by the remote WMTS, else text/xml if supported.

Also includes a handbook describing the changes.

Also includes a fix to more flexibly write out 'unclean' feature collections as GML (wrt namespace bindings/prefixes).

Also includes a fix to workaround-parse ESRI 'feature collections' with namespace.