Replacing xml file by Python files

This issue was created automatically from an original CUE issue. Further discussion may take place here.

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THe goal here is to replace the xml used for validation by a Python file.

The script will be divided in 4 functions:

• pre; defining the studies, creating the steering files, refining meshes...
  
• check_results: Comparing files, results, epsilons...
  
• post: Post-treatment generating figures from results

This will make it easier to generate new steering files and to use the new post-treatment features in postel.

Work is in progress we have the structure in place and a converter from xml to Python