Allow setting of a "label" property for networks

[Skye Welch]

I sometimes have different "identities" on the same network, meaning grouping by server hostname isn't enough. Chomp is currently making a 'temporary' label with which to group appropriate buffers: http://imgur.com/LFaFqmr

It would be nice to be able to have a user-defined "label" on a network. (I tend to use stuff like "Freenode (carrot)" or "ImaginaryNet (carrot-possel)" but people might prefer their own naming scheme).

[Kit Barnes]

I've been considering allowing multiple identities on the same network (by adding the network more than once with different identities) but it's very much not a priority at the moment. For a hacky workaround you can just use multiple hosts on the same network or, if the network only has one, add an alias for it in /etc/hosts.