On the authzperf branch: Remove the unused groups hash from the
in-memory authz structure.

* subversion/libsvn_repos/authz.h
  (svn_authz_t): Remove member 'groups'.
* subversion/libsvn_repos/authz_parse.c
  (ctor_baton_t): Add member 'expanded_groups'.
  (add_to_group, array_insert_ace, svn_authz__parse):
   Use ctor_baton_t::expanded_groups instead of svn_authz_t::groups.
* subversion/tests/libsvn_repos/authz-test.c
  (test_authz_parse): Reconstruct the expanded groups hash for display
   from those groups that are mentioned in ACEs.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/authzperf@1621707 13f79535-47bb-0310-9956-ffa450edef68