Adds a check to logic/valididate.py that checks the partial path format using a regexp. This regexp has been added to logic/path_link_name.py, therefore changing PATH_LINKNAME_REGEX to use the PARTIAL_PATH in building this regexp. Plus views/models/docs.py now uses the validation functions in the clean_ methods. Patch by: Lennard de Rijk Review by: Pawel Solyga