gajim: 1.0.3 -> 1.1.2

The list of upstream changes is huge, so I'm not pasting it here in the
commit message, but here is the upstream URL:

  https://dev.gajim.org/gajim/gajim/blob/gajim-1.1.2/ChangeLog



One of the most visible updates are the design changes for various
dialogs and the Emoji overhauls.

On our end, we now need three more dependencies, namely cssutils,
precis-i18n and keyring, which I added accordingly.

In addition, the test runner is now integrated into setup.py, which we
now use.

I also cleaned up the package expression a bit, eg. it's no longer
wrapped in a big "with lib;", so that "nix-instantiate --parse" is able
to detect attribute errors (which is very useful if you have editor
integration).

Signed-off-by: aszlig <aszlig@nix.build>