Drop Gwibber from default install

[Timo Jyrinki]

2012/3/12 Ken VanDine <ken.vandine at canonical.com>:
> For those that haven't tried the latest version, I really suggest
> getting 3.3.91 and taking that for a spin.  Most of the effort we've put
> into it recently have been quality, so no stunning changes but more
> reliability.  Duplicate detection and handling of the content.
> Scrolling and keyboard navigation has improved quite a bit, but we
> really need smooth scrolling.  I would say that would be at the top of
> the todo list.

Thanks for your efforts so far! I tried the 3.3.91 out. Sure it's the
good ol' laggy Gwibber, but at some point earlier it regressed in
usability for me so far that I stopped using it. Now it seems to be
back on track, and hopefully indeed the four bugs mentioned in the
original post will see themselves fixed at some point.

-Timo