Wiki - update Bea to Bianca

[Papawoob]

I have a suggestion for the wiki entry on how to update Bea to Bianca. For me the howto was fine but for a relative newbie we need to add the step-by-step on how to create the apt.conf file and how to get it where it needs to be. The rest of the command line stuff is excellent as all you have to do is copy, paste, hit enter, copy, paste, hit enter, etc..... Congrats everyone as Bianca is AWESOME!