LUN-751 Fix corner cases of unquoted urls
LUN-751 Fix corner cases of unquoted urls

* implement a filepath_to_url function that also quotes simpe quotes (inspired from filepath_to_uri)
* apply quoting before cleaning and normalizing the name. Otherwise files ending with question
  marks don't work

pbs/django-filer,pbs/django-filer,pbs/django-filer,pbs/django-filer,pbs/django-filer