Fix a minor correctness issue in the wc-wc copy code that made us copy
nodes that were only used to shadow lower layers as not-present children
of their parent.

The commit logic automatically handles the not-present case correctly, so
it merely affects database correctness. But the difference is visible
in our move logic.

Note that I reviewed the direct and indirect users of
STMT_SELECT_OP_DEPTH_CHILDREN before committing. This part is necessary to
avoid insert invalid children as incomplete during copy, while not changing
them to a not-incomplete state later.

* subversion/libsvn_wc/wc-queries.sql
  (STMT_SELECT_OP_DEPTH_CHILDREN): Really select the repository children, not
    just all children. Just like STMT_SELECT_GE_OP_DEPTH_CHILDREN already
    does.

* subversion/libsvn_wc/wc_db.c
  (get_info_for_copy): Simplify logic for adds by using more data from read_info.
     Avoid unneeded work for non-op-root-deletes, as we do want to trigger
     special behavior for them instead of seeing everything as a delete.

* subversion/tests/libsvn_wc/op-depth-test.c
  (move_to_swap): Add comment. Enable additional test. Expect the current buggy
     result.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1448781 13f79535-47bb-0310-9956-ffa450edef68