In the Python test suite, rename global variables that reference the

In the Python test suite, rename global variables that reference the
'Greek tree' repository to indicate that.

* subversion/tests/cmdline/svntest/main.py
  (pristine_dir): Rename to 'pristine_greek_repos_dir'.
  (pristine_url): Rename to 'pristine_greek_repos_url'.
  (run_tests): Track the renames.

* subversion/tests/cmdline/svntest/actions.py
  (setup_pristine_repository, guarantee_empty_repository,
   guarantee_greek_repository): Track the renames.

* subversion/tests/cmdline/svntest/sandbox.py
  (Sandbox.*): Track the renames.

git-svn-id: http://svn.apache.org/repos/asf/subversion/trunk/subversion/tests/cmdline@982959 13f79535-47bb-0310-9956-ffa450edef68