Retransmit timings

The retransmit values are not fast enough for modern networks. Instead of 20 or 40 seconds, it should be somewhere between 1-4 seconds (to be discussed)

These should be configurable on a per-connection basis

These should be in milliseconds to allow greater precission.

Refined retransmission might would to improve battery life on hand held devices.

 Experimentation is needed.

RFC 2988: "Computing TCP's Retransmission Timer" http://www.hjp.at/doc/rfc/rfc2988.txt