Dead code removal, eliminate extra hash calculations and clean up style.
Fix 'not enough work' misbehaving and ban behaviour.
Disconnect version 2.0.2.1 clients.
Increase receive and send buffers and getblocks limits.
Bump version number to 2.0.3.1.
Fix a typo.
Merge pull request #9 from danbi/master

Update wallet to 2.0.3.1