Model Database 0.1

models.py -> qubalapp model database 0.1
Database Model 0.1 working

admin.py -> Model classes are registred and imported for using them in
the Admin backend.
model.py -> All Qubalapp classes created (v 0.1)
Admin backend error with Achievement IDs

There is an error triggered when we try to create an Achievement.
Fixed some problems when fields were forced to be NOT NULL

Also the admin view for Course is being commented out for not overriding
the options and make it clearer...
Merge pull request #5 from radicalgraphics/model-design

Model design