remove need for json file

[phtj]

At the moment we have a json file with some settings
This is used by teh grader for doing the grading

Creating this json file is more work, and error prone

Instead of a json file we can do the following:

• The grader opens the answer model and checks what parameters there are
• The grader randomly chooses some values for these parameters and executes the model
• The grader checks the model attributes
  • If there is a model attribute called "answer_type=console", then it will set "console=true" and "model=false"
  • in all other cases it sets "console=false" and "model=true"
  • it always sets "normalize=true"
• The grader executes the answer model
• The grader applies the same parameters to the student model and executes it
• The grader compares the models