Release 2.4.8

• Engine:
  • Use appropriately the executionError field instead of
    compilationError to store entities' run time errors.
• Worlds:
  • ConsWorld: new subclass of BatWorld dedicated to recursive lists.
• Pedagogical content:
  • recursion.cons: new lesson on recursive lists (17 challenges)
  • #349, #355 : French typo
  • #356: write 'one', not '1' (was too similar to 'l') (fix #356)
  • #365: SelectionSort: don't sort the last cell, it's already done