unify fundraising@ and grants@ into grants@

Right now we have two aliases, fundraising@ and grants@, and they go to nearly the same people but not quite:

grants:      isabela steph sarah arma sue al jon bekeela gaba pili              
fundraising: isabela steph sarah arma sue al jon alison erin                    

I'm going to add erin to grants@, and then make fundraising simply point to grants@.

We've checked with alison and she's ok falling off the alias, since she's focusing on LFP these days. We can always add her back whenever we or she wants.