Convert remaining network-byte-order "uint<N>_t"s into "ovs_be<N>"s.

Convert remaining network-byte-order "uint<N>_t"s into "ovs_be<N>"s.

I looked at almost every uint<N>_t in the tree to determine whether it was
really in network byte order, and converted the ones that were.

The only remaining ones, modulo my mistakes, are in openflow.h.  I'm not
sure whether we should convert those, because there might be some value
in remaining close to upstream for this header.