swift: the multiparty transport protocol
    (aka BitTorrent at the transport layer)
    Differently from TCP, the protocol does not use the ordered data stream
    abstraction. Effectively, it splits a file into 1KB packets and sends
    them around. The secret sauce is Merkle hash trees and binmaps.

see doc/index.html for marketing stuff, ideas and rants
    doc/swift.txt for protocol draft spec
    *.cpp for the actual code
    swift.cpp is the main exec file; may run as e.g.
    
        ./swift -t node300.das2.ewi.tudelft.nl:20000 -h \
        d1502706c46779d361a1d562a10da0a45c4c40e5 -f \
        trailer.ogg
        
    ...to retrieve video and save it to a file, or...

        ./swift -t mfold.libswift.org:20000 -h \
        d1502706c46779d361a1d562a10da0a45c4c40e5 -r . \
        -h 8080
        
    ...and then point your browser at
    
        http://localhost:8080/d1502706c46779d361a1d562a10da0a45c4c40e5