Add a test case for svn_fs_dir_optimal_order.

* subversion/tests/libsvn_fs/fs-test.c
  (test_dir_optimal_order): New test case.
  (test_funcs): Register new test case.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1637397 13f79535-47bb-0310-9956-ffa450edef68
Add pro forma test for svn_fs_info_config_files.  We can only check that
the result are valid files but don't know which ones to expect.

* subversion/tests/libsvn_fs/fs-test.c
  (test_config_files): New test case.
  (test_funcs): Register new test case.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1637398 13f79535-47bb-0310-9956-ffa450edef68