[PATCH] Use consistent HTTP connection setup code throughout test suite

Hi,

the attached patch changes the implementation in mod_authz_svn_tests'
verify_get() function and uses the common http-connection setup code
from svntest.main.

This has the side-effect of resolving a test failure I was running into
when running ra_serf/https tests on my machine (see [1] for details).

Credits for this also go to danielsh, with whom the problem was
discussed on IRC.

[[[
Use the common function to create http connection throughout the test suite.

Note: This also resolves test failures when running the mod_authz_svn
tests on
certain set ups.

* subversion/tests/cmdline/mod_authz_svn_tests.py
  (verify_get): use svn.test.create_http_connection rather than its separate
   code to establish a httpd connection
]]]

Regards,
Stefan

[1] http://luke1410.de:8090/browse/MAXSVN-99