Remove stale log file
Rewrote [Log] to be more flexible.

Also, some small additions to [DHT] and [Kademlia].
DHT: further improvements

Copying MLdonkey's design, implemented all the operations having to do
with the routing table.
DHT: complete implementation

Time for testing!
DHT: actually send outgoing messages!

Also, document [SHA1].
DHT: fix two small bugs

- [SHA1.of_z] : [Z.to_bits] can have trailing zeroes
- [DHT.parse_response] either "nodes" or "values" can not be present
Log: get rid of log levels
DHT: fix response parse bug

The peers in a response to a get_peers query comes in a list of strings,
not all in a single string.
Update README
DHT: integrated into client

Support still highly experimental - need to introduce a good interface
for both DHT and (usual) tracker announcements.
Update README, CHANGES