Optimizations and bug fixes to r13767.
Optimizations and bug fixes to r13767.

* subversion/libsvn_ra_dav/commit.c
  (get_child_tokens): Just return the hash, not an error.
  (commit_delete_entry): If a second DELETE attempt would be
    effectively the same as the first, don't repeat it.  Also, in
    preparation for directory locking, go ahead and add the delete
    target's lock token to the list sent to the server (in addition to
    the children already being sent).  Finally, don't leak the error
    we get from the first DELETE attempt.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@853854 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion