[fix bug 931072] [fix bug 931150] [fix bug 938041] NGReport submission.

* Adjust the urls of the new reporting system.
* Integrate the report submission form with backend.
* Remove fixtures from reports app.
* Add tests for the submission form of the Continuous Reporting system.
* Changes to NGReport model factory.
* Ignore dirty submodule django-offline-compressor.
* Add waffle flag to edit and delete report views of the CR system.
[fix bug 931072] [fix bug 931150] [fix bug 938041] Enhanced NGReports tests.