Torbutton should have 2 sets of proxy settings

For users in an environment where their non-tor browsing also requires proxy settings, it would be nice if Torbutton had a way to specify this so these users would not need to muck around with switchproxy or other extensions that may or may not end up randomly getting their Tor state confused.

I'm thinking the best way to do this is to divvy up the proxy settings box into two tabs, Tor and Non-Tor.

Tentatively marking this as 1.2, since it probably is a popular feature and I'm not sure if we break when used in conjunction SwitchProxy or not.

[Automatically added by flyspray2trac: Operating System: All]