Record 'None' for when client doesn't supply a version, to make the math easier.
0.3.0
Fix munin plugins, record client versions in usageDB.
0.2.1
* listen on IPv4+IPv6 properly (12)
0.2.0
* listen on IPv4+IPv6 socket by default (12) * enable SO_KEEPALIVE on all connections (9) * drop support for py3.3 and py3.4 * improve munin plugins
0.1.2
* Allow more simultaneous connections, by increasing the rlimits() ceiling at startup * Improve munin plugins * Get tests working on Windows
0.1.1
Improve logging and munin graphing tools: previous version would count bad handshakes twice (once as "errory", and again as "lonely"). The munin plugins have been renamed.