examples: update hello_acq.c to be a true p2p version of hello that terminates gracefully

Signed-off-by: George K. Thiruvathukal <gkt@cs.luc.edu>
examples: update hello_acq.c termination logic and minor cleanup

Signed-off-by: George K. Thiruvathukal <gkt@cs.luc.edu>
memory_pool: all tracepoint events

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
memory_pool: hide warnings by default for memory leaks

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