+ Changed port to 51914 (rationale: it's 0xCACA; so okay, it's outside
      the registered ports area, but we'd never be accepted anyway).
    + Retry network sends in caca_get_event(), too.
    + Have a per-client buffer in case of network congestion. If that buffer
      gets full, just drop it and start again at the next frame.
    + Set the window title to "caca for the network".
    + Do not send the ANSI buffer's terminating \0.
    + Restore the SIGPIPE handler on close.
    + Set window size to 80x24 instead of 80x25.