Following up on r1571747 and r1571787, resolve an often reported assertion
on the user list by properly calculating a url (r1571787) and providing a
proper error when an added ancestor is not part of a commit.

* subversion/libsvn_client/commit_util.c
  (harvest_status_callback): Also check for dangling nodes when the node
    specifies the delete of a working node.

* subversion/tests/cmdline/commit_tests.py
  (commit_deep_deleted): Remove XFail and extend test.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1571795 13f79535-47bb-0310-9956-ffa450edef68