Gyuricska Milán / cloud

dashboard, vm: rework Interface forms, views and operations, add UserInterface forms, views and operations; extends Interface models and views with Vxlan support

Suggestion to eleminate RequestContext: https://docs.djangoproject.com/en/1.11/ref/templates/upgrading/#django-template-loader

dashboard, circle: register django autocomplete light and load static content for FilteredSelectMultiple widget on the proper way

dashboard, circle, network, request: upgrade and rework autocompletion, remove deprecated 'pattern' from url patterns

Changes:
* Use argparse instead of optparse: https://docs.djangoproject.com/en/1.11/releases/1.10/#features-removed-in-1-10
* convert print to self.stdout.write(), Django documents suggest it: https://docs.djangoproject.com/en/1.11/howto/custom-management-commands/#module-django.core.management

django.db.models.field.subclassing.SubfieldBase removed: https://docs.djangoproject.com/en/1.11/releases/1.10/#features-removed-in-1-10
New field classes require to call full_clean() method on Models, because the to_python() din't call automatically.
Related docs: https://docs.djangoproject.com/en/1.11/releases/1.8/#subfieldbase

dashboard, vm: fix user handling i tests, new Origin type cannot implicit convert to str, fix redirect_chain in 2FA tests, importing vm operation in __init_.py is unnecessary and and brokes the application

circle, common, dashboard, firewall, request: fix deprecated context and cache handling, get_models, and max_length type for ConnectCommand name

Details:
* get_models removed: https://docs.djangoproject.com/en/1.11/releases/1.7/#introspecting-applications
* post_syncdb removed: https://docs.djangoproject.com/en/1.11/releases/1.9/#features-removed-in-1-9
Alternative: post_migrate: https://docs.djangoproject.com/en/1.11/ref/signals/#post-migrate
* django.contrib.contenttypes.generic removed: https://docs.djangoproject.com/en/1.11/releases/1.9/#features-removed-in-1-9
GenericForeignKey and GenericRelation moved to django.contrib.contenttypes.fields module

closes #467