Add an additional language to Liferay

Adding an additional language to Liferay is not so difficult as it sounds.
For demonstration i will add the "language" en_GB (English for Great Britain)
to Liferay (5).

All supported locales can be viewed here (Java EE - Standard!!).
Technical description here

Following steps have to be proceeded:
1. Add the new language Code to "LIFERAY_ROOT_PATH"/WEB-INF/classes/portal(-ext).properties
## Language

2. If you add an completly new language you need to add an language-xx.propteries (xx=new language) file to /WEB-INF/lib/portal-impl.jar//content. In this case (en_UK) it is not nessary to add a new file because english (en) is already defined.

3. Add an Language-Image to your theme (in classis-theme: /images/language/en_GB.png)

4. Restart Liferay