splash-screen: Add ability to redirect to a splash screen URL

i18n points possible display LMS-2201

Update i18n translator documentation

Update Esperanto (dummy) translation files

Addition of 3 TinyMCE plugins to toolbar

Fixed missing polyfill buttons and adjusted layout of number input 
UX-381

UX-381

Checks for the presence of a cookie with specific values when activated,
and redirect the user to a configurable URL when it is not found, or not
with an accepted value.

To be used to display a splash screen to users upon the first visit.
It's the responsability of the splash page at the redirected URL to set
the proper cookie value before sending users back to the LMS.

fixed conflict between Annotator and internationalitation

i18n Sequence XModule

pep8/pylint cleanup on symmath/formula.py

Ora page object retries even if rubric doesn't load

Do not translate checkbox values in html files

Anton/store video progress

Student logins to edx, plays video, selects position, closes
browser, opens video, position is restored.

BLD-385

Add a view for the field type Dict in Studio.

Change bok-choy coverage XML filename

Refactor stub implementation of LTI Provider. BLD-601. 

Fixed TOC and copyright

Move tests related to views files into views/tests.

Finish wiki i18n

unit tests to handle duplicate user registration attempts

Don't internationalize strings we use for enrollment.

Keyboard events and ARIA markup added to speed control

MixedModulestore wraps most getters, update_item, delete_item