FUNCT added default irssi configuration

Note this is managed by the irssi command itself
FUNCT set the correct nick
FUNCT use the bell to notify interesting things

Note this will only be useful if you use a reasonable terminal like xterm or
rxvt, as other fancy things like gnome-terminal will not set the urgency hint
when ringing the bell
FUNCT ring when someone mentions me
FUNCT use the solarized theme