[frontend] Significant refactor of JavaScript frontend

[venantius]

This does a couple of things:

• Loads jQuery before AngularJS, so Angular can access jQuery instead of JQLite
• Removes a host of minor JS dependencies that should all be contained within flat-ui-pro.min.js
• Removes any and all Githubissues.
• Githubissues is a development platform for aggregating issues.