memory_pool: add option to show memory leaks

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium_worker: add function to enqueue an inbound message in the queue

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
cache: fix a white space

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
cache_actor_adapter: use cached reply messages

time ./scripts/assembly_debugging/spate-saureus-fasta-gz-4x8.sh |tee log

Without message cache:
TIMER [Visit vertices for unitigs] 41.149525 seconds
real 1m54.047s

With message cache:
TIMER [Visit vertices for unitigs] 20.970461 seconds
real 1m27.290s

There is a 50% running time reduction for the code that uses the
message cache.

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

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: hide wakeups without THORIUM_WORKER_ENABLE_WAIT_AND_SIGNAL

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