More work on issue #517.  Don't set the property -- this code is untested.
More work on issue #517.  Don't set the property -- this code is
untested.

* subversion/libsvn_client/checkout.c: #include svn_types.h, for
  APR_ARRAY_IDX.
  (handle_externals): Take new arguments to support a checkout.  Parse
  the description and do the checkout.
  (process_externals): Take new arguments like above.  Destroy
  subpool when done looping.
  (svn_client_checkout): Adjust call to process_externals.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion