Translations for version 2.x

[Florian Nücke]

As MegaZine3 is now based on a plugin architecture, each plugin has it's own
localization strings in it's own file, leading to an incompatible method of
localization (i.e. you can't use the same files).

I.e. in 1.x you had one file, lang.XX.xml.
In 2.x you have multiple files, in a folder named according to the language,
XX/yyy.xml, where yyy is "megazine" for the engine internal strings,
and "<pluginname>" for the plugins (e.g., for the German strings for the gallery
plugin it'd be de/gallery.xml).

To keep the confusion to a minimum, localizations for 2.x shall be posted in the
project wiki, on the localizations page.