Made the F1 help text and the menu bar be used by the c++ engine.

It will permit me to further customize the first app run in another
commit, and they don't belong in the script anyway.
Made the game ask the language on first app run.

- Also fixed the fact that the F1 help text wasn't updated when changing
the language.
- Moved some update logic out of the draw one.
- Made the settings be written only once on first app run.
  Prevoulsy they were written until you closed the welcome window.

This feature replace the auto-language selection.