symptom: HTTP_HOST is rewritten after ForcedProxy app is called
	 which causes Location headers to have the wrong host prefix

wsgifilter -> proxyapp.py

def __call__
first line -> environ = environ.copy()

-----------

symptom: GET /opencore/tasks/tasklist/show/11 turns into
             /opencore/tasks/show/11
         ie, the first component of PATH_INFO is dropped/ignored

pasteproxy:
        path = '/'.join(
            (environ.get('SCRIPT_NAME', '').rstrip('/'),
             environ.get('PATH_INFO', '').lstrip('/')))
