On the log-addressing branch:  Provide a test case for the new
svn_fs__compatible_version function.

* subversion/tests/libsvn_fs/fs-test.c
  (test_compat_version): new test
  (test_funcs): register the new test

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/log-addressing@1511363 13f79535-47bb-0310-9956-ffa450edef68