AC-179 fixing skip links

Fix self paced course content visiblity

Fix - Bypass unnecessary logs on logging out.

Properly escape Studio base.html

Switch to SharedModuleStoreTestCase in the 'contentstore' app where possible.

Update screenshot for Help modal on Pages page

Make base.html Mako template safe by default by:
1. Add page-level default of html escaping
2. Fix escaping of all variables in base.html
3. Fix escaping of all dependent underscore templates
Also includes additional best practices for certificates and
textbooks JavaScript/Underscore in order to complete that work.

TNL-3425

ECOM-3177 fix flaky js tests on dashboard.TrackEvents

Add Drag-and-drop XBlock to requirements.

Update help text for Pages page in Studio to reflect Courseware-Course etc change

ECOM-3640 add a new info log message on program certificate task to mark successful task completion

Switch to SharedModuleStoreTestCase in the 'courseware' app where possible.

Use Course ID in logging an exception

WL-320: fixed get_template_path to work with absolute path also

WL-307: correct FAVICON_PATH setting for comprehensive theming

fixed quality violation

skipped test in CMS

changes after feedback from mattd

Pass DOM element, not jQuery object to XBlock initialisation.

Add accidentally deleted lettuce DB cache.

Install underscore from npm.

adjust comment about program certification retry

copy event on write

Specify high priority queue for credentials generation task.