Starting with jQuery for GitHub API access

Removing the github.js library as it seems easier to just write the
GitHub API requests in jQuery.  Also removed minimised underscore as
was only required by github.js.
Retrieve OPF GitHub details and repositories.

Just a bit of prototype JavaScript code to make the GitHub API calls
to get some information and add it to some global vars, and concoct
some test html table rows.
Tidied unwanted JS sources & added jQuery load..

Removed the unwanted JavaScript includes for github.js.
Added the document onload for JQuery to populate the page using
some basic OPF GitHub information.