Make pre-cooked greek repositories work with svnserve (and probably mod_dav).
The main problem is authz configuration etc. that can't be taken generically
from a pre-packaged repo template but depends on test settings.

* subversion/tests/cmdline/svntest/main.py
  (_post_create_repos): New repository setup function. The code is 100%
                        taken from create_repos.
  (unpack_greek_repos): Post-process the repo according to the current
                        test settings.
  (create_repos): Call the new function that contains the rest of the code.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1639677 13f79535-47bb-0310-9956-ffa450edef68