Add src JS files

Add src JS files

The reason for this is to make downstreams like Fedora happy. This makes
checking those files for changes against upstream for example easier.

In the progress I updated the js-libraries so I know which versions are used
for both src and minified version. This is noted in the file src_js/SOURCES

Also I deleted jsrender.js and purl.js because the were unused.

Finally I added a Makefile option to build the minified js files yourself if
you want to do so.