On the 'issue-3348-dev' branch, we start by reverting my reversion of
Daniel's original work performed for this issue on trunk.  This
effectively re-merges r1159286, r1159299, and r1160691 into this
branch.  The following is a collapsed single log message describing
those changes.  Note that Daniel chose to use a definition which
allowed directories to be included in the --cl "" results.

For issue #3348 ('Provide syntax which means "include all files not in
a changelist"'), begin the work of special-casing the handling of the
empty-string changelist name.

* subversion/libsvn_wc/adm_ops.c
  (svn_wc__internal_changelist_match): Special case the empty
    changelist name as "not in a changelist".

* subversion/libsvn_wc/diff_local.c
  (diff_status_callback): Teach the filtering about the empty
    pseudo-changelist.

* subversion/libsvn_client/status.c
  (tweak_status): Special case the empty changelist name as "not in a
    changelist", and note that this logic duplicates what's found in
    svn_wc__internal_changelist_match().

* subversion/tests/cmdline/changelist_tests.py
  (empty_pseudo_changelist): New test.
  (test_list): Run it.

* subversion/svn/main.c
  (main): Drop a validation which is already done by
    svn_client_add_to_changelist() and is now bogus.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/issue-3348-dev@1428597 13f79535-47bb-0310-9956-ffa450edef68