Merge pull request #3402 from mathjax/develop

This is version 4.0.0

Merge branch 'v4.0-beta' into develop

Update mathjax-full version in package.json

Add LICENSE, CONTRIBUTONG.ms, and README.md to the distribution files…

… list

Add mathjax-modern-font dependency

Add v4.0.0-beta.3 files from mathjax-full

Update files to v4.0-alpha.1

Merge commit '77f42d6e4' into develop

Merge branch 'develop'

Release version 3.2.0