alpha version of django models generator

[FChikh]

I provided two template versions to choose between; they present 2 different approaches: in-class definition of relations & out-class; In-class definition has problems with ordering classes in order not to make links to not yet defined classes; Out-class definition has problem with readability of code, as we add constraints to class out of main definition

[ivan-alfonso]

The "in-class definition" approach can be removed, since the classes are not ordered and this generates problems between relationships.

The "out-class definition" is a valid solution, but it is necessary to modify the template because the code generator should not modify the input model.

[ivan-alfonso]

• The on_delete parameter in the OneToOneField relationships of the model is missing and required.

• In Django it is not necessary to redefine inherited attributes in child class (in fact an error occurs). For example, the following models will not be well defined:

class LifecycleStage(models.Model):
    name = models.CharField(max_length=255)
    date = models.DateTimeField()

class Design(LifecycleStage):
    name = models.CharField(max_length=255)
    date = models.DateTimeField()
    other = models.CharField(max_length=255)

The correct way is:

class LifecycleStage(models.Model):
    name = models.CharField(max_length=255)
    date = models.DateTimeField()

class Design(LifecycleStage):
    other = models.CharField(max_length=255)