r4288: don't use struct dcerpc_interface_table anymore in the

r4288: don't use struct dcerpc_interface_table anymore in the
main rpc server code. let the backends specify a ndr_push/ndr_pull function
like we already do with the dispatch() function.

this allows an interface implmentation to work as real proxy
without needing to know the idl for an interface that means
just the plain decrypted payload can be forwarded

If someone want to write such a backend, patches are wellcome

metze