Changes to translator credits.

For a while now we had translator credits in about_window.py file. While we do the same thing with other contributors translators are an exception to this rule.

Today, I moved this list of translators to translator-credits language key in their respective translations as specified by the gettext format. Even though I'd like to keep things organized, this is the way Gnome proposes and expects things to be done.

A lot of languages doesn't have this key populated and I urge future translators to add their own name to this field. You can also provide email and URL to your site if you have one. Use the following format:

Name <email@domain.com> yoursite.com

Thanks!/email@domain.com

Alle ingangen

Titel:Datum en tijd:
Stabilization for GTK3 version.05:39:54 - 09/20/2016
Version 0.3 (build 61)14:22:39 - 01/30/2016
RPM Love...13:06:35 - 01/21/2016
Version 0.303:39:48 - 01/18/2016
Call for translators.17:13:19 - 01/06/2016
Preparing 0.3 release.11:20:18 - 04/15/2015
GitHub Wiki available to everyone.12:28:17 - 04/06/2015
Ubuntu: Broken translations.05:03:00 - 04/03/2015
Site translation available on Transifex.13:49:44 - 03/27/2015
Changes to translator credits.10:09:37 - 03/27/2015
News feeds added to the site.10:00:36 - 03/27/2015