Add time measurement in test
Add default ping event listener to irc manager

TODO: check if event has listeners already,
format of ping response (all server reply codes)
New IRCNetworkEvent as abstraction, includes IRCNetwork

IRCNetworkEvent is subclass of IRCEvent, includes as source parameter
the IRCNetwork.
Test for Rename (NICK command) update
Reply constants (RFC1459)

As initial diff base version
Update Reply constants (RFC2812)

TODO: diff, which are currently used?