Bug#1018118: transition: mutter & gnome-shell 43

[Jeremy Bicha <jeremy.bicha@canonical.com>]

Control: tags -1 -moreinfo
Control: unblock -1 by 1016706

We are ready to do this transition now that evolution-data-server 3.45
has migrated to Testing.

As in previous gnome-shell transitions, there are still lots of
packaged gnome-shell extensions that aren't compatible and will need
to be ported or removed from Testing.

https://udd.debian.org/cgi-bin/bts-usertags.cgi?user=pkg-gnome-maintainers%40lists.alioth.debian.org&tag=gnome-shell-43

Thank you,
Jeremy Bicha