Allow running the dav tests with only minimal logging enabled on Windows to
support much smaller ramdrives.

* win-tests.py
  (.): Add optional --httpd-no-log.
  (Httpd): When using nolog, only log critical errors.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1449679 13f79535-47bb-0310-9956-ffa450edef68