Fix m_cgiirc to set the user's host straight away when using WEBIRC.

Doing this at a later time defeats the purpose of WEBIRC support in the first place - we want to know their real credentials right off the bat.
Add a connect block option 'forceident' for m_ident which will force the given ident upon any user in the connect block.

This is useful for say, forcing all webchat users to have the ident "webchat".