Improved the BEEP protocol implementation: * Callbacks for replying to messages. * Starting of channels implemented. * Some error handling (though not much yet). Also, added a sample client that sends a message using the echo protocol. Finally, added a simple proxy script that outputs the peer-to-peer communication to the console.

[unittest]
test-suite = bitten.tests
xml-results = build/test-results.xml
coverage-results = build/test-coverage.txt
coverage-dir = build/coverage