Revert "Revert pull request #3466"

This reverts commit 59e3cae4c9c6f2c95a816a8280b470ec6add9486.
Fix for 500 error (undefined) in annotation tool
Using Edx version of tinymce
generate raw URLs that are not rewritten by static_replace
proxy raw further along
Merge pull request #1 from edx/db/harvardx

avoid URL rewriting
extend changes of url/raw issue to video annotions
Merge pull request #3744 from lduarte1991/lduarte-harvardx

Reconnecting Token Generator for Annotation Tool [Fix]