Remove some old leftovers
Merge pull request #77 from saradickinson/tcp_resend_bug

Thanks Sara, well spotted!
Fix 2 small bugs with resending tcp data
recv, write and sendto return ssize_t
declare inline functions in a more portable way

Or at least in a way that works without a -O[1-3] flag...
TCP fast open support (linux only). Enabled with --enable-tcp-fastopen configure option.