The packet size in netio_tcp_send/netio_tcp_recv might not be 32 bits

[flaviojs]

The comment says:

// very simple protocol to send packets over tcp
// 32 bits in network format - size of packet, then packet itself and so on.

but it uses the u_long type, which is typically either 32 bits or 64 bits.
Only causes problem when systems with different u_long sizes try to communicate.

Discovered while converting to rust.