[FEATURE] Add UntypedMetricFamily
[FEATURE] Allow start_http_server to take a registry, for use in multiprocesses setups
[ENCHANCEMENT] Don't log requests to WSGI server
[ENCHANCEMENT] Improved error handling when prometheus_multiproc_dir isn't set
[BUGFIX] Handle /proc/self/fd not being accessible
[BUGFIX] Workaround urlparse bug in Python 2.6