Recreate pot and po files

Although we have already string freeze, we need to recreate the
translation files again.

* These changes remove the 'Ok', instead we will only have 'OK'
  One way of spelling removes the burden of translations.

* We introduced 'Trade' as engine string. This is most often already
  translated, so it was just uncommented most of the time.
translation-de: shorten mouse button names.