Following up on r1431352, apply some simplifications in the copy code.

Perform the mixed revision test for moving trees with tracking once per move
instead of once for every directory moved.

* subversion/libsvn_client/merge.c
  (ensure_wc_is_suitable_merge_target): Use proper format for svn_revnum_t.

* subversion/libsvn_wc/copy.c
  (copy_versioned_file): Remove unused argument.
  (copy_versioned_dir): Move the mixed revision copy test to the caller, and
    remove now unused arguments. Update caller.
  (copy_or_move): Remove unneeded checksum handling. Perform the mixed revision
    test here. Use proper format for svn_revnum_t. Update caller.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1431368 13f79535-47bb-0310-9956-ffa450edef68