On the 'issue-3348-dev' branch, make `svn commit --cl ""` commit all
files not assigned to a changelist.

* subversion/libsvn_client/commit_util.c
  (harvest_status_callback): Handle the special-casing of the
    empty-string changelist name, taking care not to include directories
    in the list of committables which match that changelist filter.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/issue-3348-dev@1428629 13f79535-47bb-0310-9956-ffa450edef68