add pack/unpack capability to map

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
add sort function for vector

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
add coverage distribution actor

Link: https://github.com/GeneAssembly/biosal/issues/56
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
configure the number of expected messages

Link: https://github.com/GeneAssembly/biosal/issues/56
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>