fix nick() should set client.me test (on next event loop proccess)
rename "nick" event to "welcome"

In order to support a nick event on the NICK command

:WiZ!jto@tolsun.oulu.fi NICK Kilroy
	- Server telling that WiZ changed his nickname to Kilroy.

From;
http://tools.ietf.org/html/rfc2812#section-3.1.2