Increase async script timeout in lettuce tests

Increase the default timeout for waiting in lettuce tests

Extract opaque_keys into a separate library

Make TinyMCE's HTML source code editor work under Internet Explorer

DOC-362, another set of students who don't get email

Fix exception on Internet Explorer when adding first transcript language

Fix ChoiceTextResponse.

JavascriptResponse i18n.

Added trailing slashes to verify_student app urls.

Do not persist anonymous ids when exporting for all students of a course.

ChoiceGroup  i18n.

As TinyMCE's CodeMirror plug-in uses 'window.location.origin' which is not supported by Internet Explorer, the HTML or raw code editor does not work under Internet Explorer.
We need to create one in order to make these vendor codes work under Internet Explorer.

Two image references incorrectly preceded by a comment

Parse urls with query params for ^/static

i18n of Image Response [BLD-723]

  Query params with a value that starts with /static should have their values converted to the full location.
  Query params with a value that does not start with /static should be left unchanged.

Add tests for has_course

Dhm/opaque dont skip

For large courses this causes export to take a long time and to time out.

LMS-2747

Internet Explorer throws an "Invalid argument" exception when uses an empty string as the parameter in ```namedItem``` method.
Change empty string into null value can maintain browser consistency.

[LMS-2571]

Fix paver python prereq paths

Fixed change log table format & pdf errors

i18n: Make values that has 'display_name' be displayed localized in editor

Opaque keys

Dhm/no package

and negative tests for get_course.

STUD-1592, STUD-1603, LMS-2642