Add additional functions to IRC input

Adding 

* The ability to catch all events - this includes PRIVMSG to Logstash, QUIT/JOIN/PARTs
* Add the ability to send number of users per channel stats into the logstash pipeline on intervals

It is better to save the reference to the thread in an instance variable so we can stop it later in a teardown method. We can replace the thread creation and the interval check with helpers methods from the `Stud` library. (https://github.com/jordansissel/ruby-stud)

@request_names_thread = Stud::Task.new do
end