move scheduling code in the scheduler

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
implement symmetric actor scheduling

Link: https://github.com/GeneAssembly/biosal/issues/364
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
use symmetric aggregator with no persistent storage

scripts/development/run-argonnite-1-28.sh
node 0 efficiency: 0.91
real    33m56.759s

Link: https://github.com/GeneAssembly/biosal/issues/366
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
increase balancing period

Link: https://github.com/GeneAssembly/biosal/issues/367
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
balance things only if necessary (check load percentiles)

scripts/development/run-argonnite-1-28.sh
32m

Link: https://github.com/GeneAssembly/biosal/issues/368
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>