GtkNotebook scrolling usability

[Cody Russell <bratsche gnome org>]

So, right now GtkNotebook allows you to change tabs by using the mouse
wheel.  Once I noticed this and the more I thought about it, it really
seems like a terrible feature and one that may be detrimental to
usability.

I talked to Matthias briefly on irc, and he seemed to agree.  He
suggested that maybe there's a use for it in the case that you have a
ton of notebook tabs open, but I'm not quite convinced.  Just wanted to
post on the lists and see if people have thoughts on this, otherwise I'm
probably going to file a patch to either rip the feature out or at the
very least make it so we can disable it. :)

/ Cody