Added Septag to cfg, NicktoIgnore now chan var.

Added a new Septag option to config that that separates the nick/channel
and network variables when both are enabled (e.g.
{Person<sepTagn>Netname} or {#chan<sepTagc>Netname}).
Other changes: NickstoIgnore is now a channel setting instead of global
setting; tweaked text events a bit more for consistency