create a branch where the dev of the nodesk_template app
will take place.

This app is the app that will manage the template file of nodesk,
their models etc.
add some skeleton code for the template management
switch from a unique django model file to a directory of models
add nodesk_template exception file and its first Exception
(unrecognized type of a field of the template)
update the model manager (still WIP)
update of the model manager (WIP)
All the function in field_types.py has to be defined yet
update of the function generating the model of
the different template : for now the generation is simple but it works
take care of checkbox and radiobox types.
Next I'll take care of types options
Tentative refactoring.
Rename identation to indentation (huh.)
Small fixes (import exception, typo and use of splittext).
model_string replaced by function
Add 'tests' directory.
Use constants.INDENTATION.
Move tests/test_*.py to tests.py.

+ move tests/data to test_data.

(Because django doesn't like that tests/ directory.)
Fix imports and data path.
Don't assert a function against itself, you moron.
Unused import.
fix imports + forgot quotes in simple_field.
remove copy of template_test.yaml