Indicate which buffer is selected in the buffer list.

Does not indicate if a network status buffer is selected as `[data-buffer-id]` is attached to the `.network-name`. Not sure if I should add `.selected` to `.network` or `.network .network-name`.

Renamed `.active` in the LESS (which was probably meant for this?) to `.channel.selected` as `.active` is used in bootstrap.

![](http://i.imgur.com/6Gf9BKC.png)