Upgrade `requests` module to 2.3.0
Upgrade `requests-oauthlib` to 0.4.1
Upgrade `oauthlib` to 0.6.3
Add argument.
log stop_video event
The LMS should serve favicon.ico also when a theme is enabled.
Annotation Tools: Removed background-color from image annotations

- Also fixed edit bug when annotation is not created first
- Also fixed indentation issues
XBlocks can disable navigation chrome.

There is an option to:
* Enable/disable accordion navigation
* Enable/disable/repoint tab navigation

This allows for full-screen XBlocks (e.g. a code IDE, or large video
player). It is also the first pass at allowing top-level XBlocks. It's
also now possible to make a chromeless XBlock, point a tab to it, and
make it point back to that tab.

Next steps down that path would be:
* Fix up how tabs are handled. The current version is a hack.
* Create appropriate XBlocks for courseware, tabbed navigation,
  etc. to reach feature parity
* Invert/rejigger the XML format.
Removed suppress_top_level_nav, as per Cale
Explicit disable_accordion
Review from Cale
Review from Cale
Fixes: DOC-392, shared preface listing resources for different types of audiences
Merge pull request #4164 from edx/ahodges/documentation/DOC392

Draft for DOC-392
Annotations Tools: Commented OSDA code and added clarification to catch changes
Corrected all links in preface, added to dev and data guides
Added mising tinymce.js to static_htmlbook.html.

LMS-2848
Pass storage_url and token values as parameters to StudentNotes init.

LMS-2848
Add Tamil language
Add Amharic language