Added an example plugin.

This plugin comes from RayPlatform-example.

The example is activated with the -example option. Will work without input sequences.

Signed-off-by: Charles Joly Beauparlant <Charles.Joly-Beauparlant@crchul.ulaval.ca>
Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
MachineHelper: registerPlugin and resolveSymbols must be last

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>