Degrade cross-wc moves to a copy+delete. We cannot currently track cross-wc
moves, and trying to do so leaves a broken move in the source WC.

Found by: danielsh

See for related discussion:
http://svn.haxx.se/dev/archive-2013-01/0147.shtml

* subversion/libsvn_wc/copy.c
  (copy_or_move): Add a new optional output parameter move_degraded_to_copy
   to let the caller know whether a move had to be degraded. Set this parameter
   for cross-WC moves.
  (svn_wc_copy3): Pass NULL for move_degraded_to_copy.
  (svn_wc__move2): If we find that a move has been degraded to a copy, perform
   a regular deletion of the move source.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1430272 13f79535-47bb-0310-9956-ffa450edef68