recursion.cons.{Min,Increasing}: new exercises
Enough RecList exercises. Note the remaining as TODO and proceed
fix po4a's configuration
rerun po4a, no real change
unfuzz fr translation, and rerun po4a
regenerate the engine translation (no real change)
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