resync the engine translation
Release 2.2.2 (the 2s version)

This is a bugfixing release.
  * welcome.LoopCourse: specify that the colors get updated automatically
  * welcome.NearHundred: fix french translation (was plainly wrong)
  * welcome.SlugHunting: align templating and mission: isFacingTrail must be copied
  * welcome.Variables: scala mandates an initial value (fix #109)
    plus various small improvements
  * Unify all Dave messages (marking functions that are forbidden in a
    given exercise -- like setPos in maze exercises), to ensure that
    they are properly translated despite the fact that gettext don't
    dig into scala and python files for string to translate.
  * Specify a working font for plain text to help the poor Mac users
  * welcome.RunHalf: fix the scala templating
  * welcome.FlowerPot: fix the french translation (growFlowers with a s)
  * FeedbackDialog: reset the text on each invocation
  * welcome.MethodsArgs: Fix a faulty copy/paste in scala prototypes
  * welcome.LoopFor: Fix the scala syntax of for loops
  * welcome.RunHalf: the description and the given condition did not match