Fix joal-demos Issue1, Issue3, Issue4 & Issue5

Issue1:  broken relative links from lesson*.html to the rc12 jnlp files. i will prepare a new pull request to fix.
Working jnlp using rc12 files for joal-demos lession 1, 2 ,3 & 5 are available here:
https://jogamp.org/deployment/jogamp-current/joal-demos/jnlp-files/

TODO: Issue2: The jnlp for lession 8 it appears broken.  8 depends on a missing thrid party library and a test ogg file.

Issue3: the lesson*.html links to upstream DevMaster OpenAL lesson 1-8 are broken.
The following devmaster URL's appears broken:
http://www.devmaster.net/articles/openal-tutorials/lesson1.php
... to
http://www.devmaster.net/articles/openal-tutorials/lesson8.php

Issue4: The source code in
https://jogamp.org/joal-demos/www/devmaster/lesson1.html
... to
https://jogamp.org/joal-demos/www/devmaster/lesson8.html
needs to be updated to match the source-code inside joal-demos git.

Issue5: Switch the sourcecode for lessons 1,2,3,5 & 8 git link at the
https://jogamp.org/joal-demos/www/
sidebar from github -> jogamp.org