biosal_unitig_unitig_manager bug

The value of CONFIG_UNITIG_USE_MULTIPLEXER was not
respected.

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: add option -actor-ratio

This option sets the "number of actors per node / number of node" ratio.
A manager actor can use this to spawn enough actors so that the multiplexer
yields good DOA (degree of aggregation).

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
scripts: test option -actor-ratio

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>