Bug#1089127: gnome-core: Install locales-all by default

[Jeremy Bícha]

Source: meta-gnome3
Version: 1:47+4

Test Case
-------------
Goal: Install Debian in English then switch the UI to a different
language, such as French.

After install, open the Settings app. Click System in the sidebar.
Click Region & Language then Language.

The list only has English.

How It Works Currently
------------------------------
The Debian Installation Guide [1] recommends using a preseed file to
generate additional supported locales.

The Debian Reference [2] says that you can run
dpkg-reconfigure locales
and make sure that all the languages you want to use are checked.

[1] https://www.debian.org/releases/stable/amd64/apbs04.html#preseed-l10n
[2] https://www.debian.org/doc/manuals/debian-reference/ch08.html#_the_reconfiguration_of_the_locale

Suggested Improvement
---------------------------------
I don't think that either of those methods are friendly to end users.
I believe that it should not be required to use a terminal to use
Debian with the GNOME Desktop.

I think an ideal fix would be to rework gnome-control-center to show
all the locales and run dpkg-reconfigure locales (or its equivalent)
if a locale is chosen where support isn't already available. This
could additionally install additional packages like spellchecking
dictionaries, thesaurus, LibreOffice help, etc for that language. On
Ubuntu, this functionality is provided by language-selector-gnome
which is a separate app linked to from gnome-control-center.

Since no one has done this yet even though this functionality has been
missing for many years, I instead suggest that we install locales-all
by default. Using locales-all is suggested as an alternative in the
Debian Reference [2]. It says we might need to be careful to also
explicitly install the locales package (which currently is installed
by default).

Therefore, my proposal is that we have gnome-core add Recommends:
locales-all . That would allow users to uninstall it if they really
want to. apt tells me that locales-all has a download size of 11 MB
and an installed size of 241 MB. I think if Debian were particularly
concerned about the space that translations take up, Debian could
implement something like the language packs that Ubuntu uses. I don't
think we are particularly concerned about the size of the default
GNOME desktop in Debian right now.

Thank you,
Jeremy Bícha