Feature flagged enrollment counts on instructor dashboard.

* enrollments counts removed from legacy dashboard
added tests for instructor_dashboard.py, added docstring for _is_small_course, removed check for settings.ANALYTICS_DASHBOARD_URL when creating dashboard link
Pylint: ignore TODO comments
Disable TODO comments in `paver quality` only
Disable FIXME errors on `paver run_quality`

Not on `paver run_pylint`
fixed quaility errors in instructor_dashboard.py, moved test_instructor_dashboard under tests/views directory
Set up validation_messages so that it goes through the RequireJS optimizer.
Simply check for existing text and type.
Clarify types of Python values.
Prevent instructors from accidentally downgrading enrollment modes through instructor dash TNL-804
avoid annonymous user from redirecting to survey form
WL-150
Merge pull request #5923 from edx/zub/bugfix/wl-150-survey-form-error-on-info-page

avoid annonymous user from redirecting to survey form
Merge pull request #5913 from edx/adam/prevent-accidental-course-mode-downgrade

Prevent instructors from accidentally downgrading enrollment modes throu...
Merge pull request #5881 from edx/christina/notification-requirejs

Use factory file so JS used by studio_xblock_wrapper.html goes through RequireJS Optimizer
Merge pull request #5838 from edx/dsjen/feature-flag-analytics-enrollments

Feature flagged enrollment counts on instructor dashboard.
Merge pull request #5814 from edx/disable-pylint-todo-comments

Pylint: ignore TODO comments
Changing event suppression to signal suppression.

Code review changes.

Fix test and pylint.

pylint error.

Updating the test to verify the signal is fired.

Test for all analytics events

Import pylint error.

Pylint error
Merge pull request #5720 from edx/sanchez/avoid_event_suppression

Changing event suppression to signal suppression.