Addition of 3 TinyMCE plugins

The following plugins added to toolbar in Edit of Unit:
 - fontselect
 - forecolor
 - image
fixed conflict between Annotator and internationalitation
Change name of bok-choy XML coverage report to avoid combining it with the unit test reports
Do not translate checkbox values
Ora page object retries even if rubric doesn't load
Merge pull request #2536 from edx/will/bok-choy-coverage-name

Change bok-choy coverage XML filename
BLD-658: Add view for field type Dict in Studio.
Merge pull request #2478 from edx/anton/add-view-for-dict-in-studio

Add a view for the field type Dict in Studio.
Persist student progress in video.

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

BLD-385
Merge pull request #2365 from edx/anton/store-video-progress

Anton/store video progress
pep8/pylint cleanup on symmath/formula.py
Merge pull request #2549 from edx/zoldak/things-not-to-translate

Do not translate checkbox values in html files
Merge pull request #2558 from edx/will/more-robust-ora-page

Ora page object retries even if rubric doesn't load
Merge pull request #2538 from edx/sarina/fixup-symmath

pep8/pylint cleanup on symmath/formula.py
i18n Sequence XModule
Merge pull request #2560 from edx/sarina/fix-i18n-xmodule-sequence

i18n Sequence XModule
Merge pull request #2493 from danielcebrian/daniel-branch-fix

fixed conflict between Annotator and internationalitation
splash-screen: Add ability to redirect to a splash screen URL

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 missing polyfill buttons, adjusted layout of number input in component editor
UX-381
Merge pull request #2561 from edx/frances/studio/bug-editor-number-layout

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