test: issue2551366. Probe for open port in test_liveserver.py Add a method to probe for an open port to wsgi_liveserver.py. Start the roundup server under wsgi on the open port. If a port can't be found, it skips all tests. Also changed all hardcoded URL references to use the dynamicly determined tracker url/port value. I fed my patch to wsgi_liveserver.py upstream at: https://github.com/jerrykan/wsgi-liveserver/issues/3

#!/usr/bin/env python
from __future__ import print_function
import zlib, base64, sys
print(base64.encodestring(zlib.compress(sys.stdin.read())))