Put logging messages in the ping-pong tutorial.

These messages permits to show how the demo is progressing. These
messages are not given in the tutorial's text.
Fixing the behavior of the english auction tutorial.
Add Perl script that help to run the demos.
Add launching scripts and fix the demos to be runnable.
Fixing the demos.
Remove unnecessary Java code.
Fixing the package name of the Ping-Pong in a subcontext.
Apply code style fixes.
Remove the dependency to Janus in the POM.
Update the POM configuration for the new version of SARL.

Signed-off-by: Stéphane Galland <galland@arakhne.org>