* Removed the concept of "no bandwidth limit" - if none is specified, its
16KBps in/out.
* Include ack packets in the per-peer cwin throttle (they were part of the
bandwidth limit though).
* Tweak the SSU cwin operation to get more accurrate estimates under
congestions.
* SSU improvements to resend more efficiently.
* Added a basic scheduler to eepget to fetch multiple files sequentially.
