Adding a new variable to
   sophomorix.conf
   *.school.conf


1) Add the variable to the master file

   A) The master file will be read first by sophomorix
      in &read_master_ini();
      ### (new variable apears)

   B) The master file ist copied

   C) Then the config file is read and the copied master file updated
      in &check_config_ini();
      
      Updated are Sections/Parameters that

      - are a valid combination (existing in the master file)
        ---> continue to C

      - if its not valid (not existing in master file)
        ignore it/exit it

      ### (new variable is there from master file, perhaps overwritten from config)
 
   D) load the data from B) into sophomorix_config

      - check the data
        (i.e. if filterscript is existing and executable)
      - put the data in the correct place in sophomorix_config
      - put redundant data in sophomorix_config for easier lookup

     ### (new variable is in in sophomorix_config)

    