Codemirror is used in the raw html block to make the edit window more like a text editor

Currently codemirror.js is installed with the javascript package being downloaded into the libraries folder and just laying there. This means that we never get any notifications about when it receives new updates. Also installing javascript libraries this way is so 2010. It would be nice if it can be installed with npm like most javascript packages are installed today. This would require some look into how to use npm with python/django

This issue is similar to #727