Web Inspector: Add ESLint open source library to the inspector
https://bugs.webkit.org/show_bug.cgi?id=137714

Reviewed by Timothy Hatcher.

This adds the eslint.js external library for static analysis and the necessary license.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@174721 268f45cc-cd09-0410-ab3c-d52691b4dbfc