Add two failing testcases on ugly corner cases of committing moved
descendants.

* subversion/tests/libsvn_wc/op-depth-test.c
  (commit_moved_descendant): New function. Shows that it is impossible to
    commit certain kinds of moves at this time.
  (commit_moved_away_descendant): New function. Shows that commit allows
    breaking certain kinds of moves at this time.
  (test_list): Add new tests.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1444745 13f79535-47bb-0310-9956-ffa450edef68