Adds +W to chanmode to enable archiving

Setting +W on a channel will enable logging to local file on server.
Format is JSON and compatibel for Logstash 1.2. All servers will log
local messages.  Expected to be shipped to central logstash (or
similar) to get one complete log.
Use Atlassian Crowd for authentication

Adds support for using Crowd from Atlassian as a way of authenticating
users for logging into the irc server.