New "stable" release: many improvments amongst the following
  * a student can add his photo
  * about rgpd
  * student can see his activities
  * the link "mailto the teacher" can be desactivated
  * new things in the score tables of a user, in particular,
  a bar which shows the evolution
  * new ergonomy for the "livret"
  * a new class in italian
  * possibility to add a tool in a class
  * new glossary (preliminary version), possibility 
    to make supervisor own glossaries from this one
  * possibility to add icons before the exercises of a sheet
  * new ergonomy to choose the bareme of a sheet
  * some tables can be sorted
  * new things in technical variables
  * possibility to repeat an exercise with the same data
     up to a limit and if the answers are not good
  * possibility to limit the number of tries on an exercise
  * new slib
and so on ...

Thanks to all contributors and to all testers (in particular
 Sophie Lemaire).