On the authzperf branch: Validate rights in access entries.

* subversion/libsvn_repos/authz_parse.c
  (add_access_entry): Verify that any entry that grants write access
   also grants read access.
   Remove a fixme comment and add a missing space to an error message.

* subversion/tests/libsvn_repos/authz-test.c
  (test_authz_parse_tng): Print the whole $anonymous and $authenticated
   access rights if they're different from the common denominator.
* subversion/tests/libsvn_repos/authz.rules:
   Fix access entries that fail validation under the new rules.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/authzperf@1618666 13f79535-47bb-0310-9956-ffa450edef68