Fix issue 4293, delete/move with file external in unversioned dir.

* subversion/libsvn_wc/wc-queries.sql
  (STMT_INSERT_DELETE_FROM_NODE_RECURSIVE,
   STMT_INSERT_DELETE_LIST): Ignore file external rows.

* subversion/tests/libsvn_wc/op-depth-test.c
  (move_delete_file_externals): New.
  (test_funcs): Add new test.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1461084 13f79535-47bb-0310-9956-ffa450edef68