Handle unversioned-not existing targets properly from the working copy status
walker, by returning the 'svn' expected error for this case.

* subversion/libsvn_wc/status.c
  (svn_wc__internal_walk_status): Handle the completely unknown case properly.

* subversion/tests/cmdline/commit_tests.py
  (commit_unversioned): Remove XFail marker. Update expected error. Remove unneeded
    whitespace.

* subversion/tests/cmdline/stat_tests.py
  (status_for_nonexistent_file,
   status_not_present): Expect unmodified output, but a warning on stderr.

* subversion/tests/cmdline/tree_conflict_tests.py
  (import): Import run_and_verify_svn2.
  (ensure_tree_conflict): Ignore warnings for completely unknown nodes.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1489928 13f79535-47bb-0310-9956-ffa450edef68