Adding packages to ubuntu-desktop packageset

[Marco Trevisan]

>> Here are the packages I can argue for desktop-extra:
>> 
>> * gnome-shell-extensions is a set of extensions curated by GNOME
>>   upstream; it does not define the GNOME OOTB experience, but it is
>>   somewhat of an official alternative experience?
> 
> Surely these are extensions and therefore not part of the default GNOME
> experience?

They can be enabled easily, although they are not the default (at least
unless you don't consider as official the gnome-session-classic).

However, one reason for having them under our umbrella is mostly the
fact that they are a quite easy package to maintain but they are often
blocking our updates to gnome-shell major versions, given that the
package by default depends on the latest version.

So, given that we already have responsibility on the main shell
component, having these too would just reduce the burden on core
developers.