"Further application" contains dead links

[cniesen]

The "Further application" links to Theremin and Photobooth are dead and return a 404. It would be nice if @DieterHolz could restore the projects if they are still relevant. Otherwise I'd suggest removing the links (see occurrences). Thanks.

Example:
https://www.pi4j.com/examples/components/simplebutton/

[DieterHolz]

These links can be removed. Both projects are completely out of date.

[cniesen]

Thank's @DieterHolz .

Pull request #68 created.

[eitch]

PR merged