Made the app be runnable on its own without related project.

This makes it far easier to test and to migrate to CMS 3
Hvad migrations.
Removed some unrequired code. E.g. simple_translate.py
Added plugin template.
Fixed urls.
Updated requirements and settings.
Updated standart cms template from the test app.
Updated factories, admins and fixed tests.
Updated view templates.
Renamed table to fix cms deprecation warning.
Flake8 cleanup.
Fixed migration order and dependencies.
Removed migration dependency again.
Increased number of cms migration dependency
Updated get_files_for_document template tag to make more sense.
Updated docstring.
Updated requirements.
Saved the document language on the file.
Merge branch 'develop'
Released v1.0