secure-cookies: Allow to use secure HTTPS cookies (Django setting)

Cf https://docs.djangoproject.com/en/1.4/ref/settings/#std:setting-SESSION_COOKIE_SECURE
Updated help link and content of container page
Don't set 'download_video' field on importing video from xml until explicitly set
TNL-324
update video module to always set download_video field on export
Make code more robust to bad input (for case where DB was populated with string None)
Image Annotation Tool: Fixes _isOpenSeaDragon function
Annotation Tools: Pylint Fix left over from previous PR
Properly Setting ANALYTICS_DASHBOARD_NAME for AWS
Merge pull request #5352 from edx/insights-name-fix

Properly Setting ANALYTICS_DASHBOARD_NAME for AWS
Fixed transcript not follow with video on seek.
TNL-235
Merge pull request #5294 from edx/waheed/tnl235-fix-video-transcript-not-follow

Fixed transcript not follow with video on seek.
Don't allow commenting while the thread is closed

When someone closes thread there is still option to add
comment which cause error when submitted. User shouldn't
be able to comment while the thread is closed.

TNL-150
Merge pull request #5142 from mlkwaqas/waqas/tnl150-stop-comment--on-closed-thread

Don't allow commenting while the thread is closed
Merge pull request #5240 from edx/zub/bugfix/tnl-324-downloadvideoexportimport

Don't set 'download_video' field on importing video from xml until expli...
New post should show category/subcategory breadcrumb when created.

When the new post is created under the subcategory and it appear
after the creation, it doesn't have the link of category/subcategory
after thread body. When we reload the page the link appears. Link
should appear after creation.

TNL-404
Remove JSDraw
Remove mentions of JSDraw from the test data
Merge pull request #5279 from mlkwaqas/waqas/tnl404-new-post-hidden-breadcrumb

New post should show category/subcategory breadcrumb when created.
Annotation Tools: Non-critical highlights == undefined fixes

i.e. they should be fixed but don’t cause the whole thing to break.

 - PR fixes

 - Reverted Fix
Making the django main template navigation course aware.