Signed-off-by: Mattia Rizzolo <mattia@debian.org>

Adding gettext module to manage translatable strings.

Chris Lamb authored Sep 09, 2017 and Jonathan McDowell committed Nov 06, 2017

This fixes somewhat ugly grammar of, for example:

  "You are currently Debian Developer, uploading and you cannot
   become Debian Developer, non-uploading."

to

  "You are currently a Debian Developer, uploading and you cannot
   become a Debian Developer, non-uploading."

Thanks to Chris West (Faux) <debian@goeswhere.com> for pointing
this out on IRC.

Closes: #875128

'Cancelled' could be argued the American way, but since the internal spelling
is en_GB I concluded that it is what the author intended.