CONNT-34: Updated implementation for active_link Django template tag:

- Added possibility of passing-in the view positional and keyword
arguments.
- Updated inline documentation.
- Implemented tests.

CONNT-34: Rewrote current_url_equals implementation:

- Implemented tests.
- Simplified implementation.
- Added proper support for passing-in arguments to the view being
checked.

CONNT-25: Updating application and project to use Django 1.11.x:

- Bumped Django version in both the development requirements and setup
script to 1.11.x.
- Bumped Django Crispy Forms to version 1.7.0 in both development
requirements and setup script.
- Updated import of URL-related modules to use the new path (previous
one is deprecated).
- Added explicit on_delete = models.CASCADE option to all foreign key
fields (old implicit behaviour will be deprecated in Django 2.0).
- Fixed the custom change_list.html template used in Django Admin to
render without errors.

CONNT-25: Updating application and project to use Django 1.9.x:

- Updated the html_link tag implementation to produce safe output, and
added tests for it.
- Updated URL configuration in both the application and test project
according to deprecation warning.
- Updated views that return customized forms to ensure the form_class
passed in to get_form is optional.
- Bumped Django in both setup script and development requirements to
version 1.9.x.
- Updated test project configuration to match the version produced by
Django 1.9.x admin commands.