On the 1.6.x-issue2267 branch, fix issue #2267, "support svn:externals
on locally added directories".

This is technically a backport of r946661, but it had to be rewritten.
So I've done a record-only merge of r946661 from ^/subversion/trunk
to officially merry this commit to its husband on trunk.

* subversion/libsvn_wc/adm_crawler.c
  (report_revisions_and_depths): If a locally added directory has
   an svn:externals property set on it, include the externals in
   traversal info. This makes our caller pull the externals into
   the locally added directory as part of the update.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.6.x-issue2267@946826 13f79535-47bb-0310-9956-ffa450edef68