handshake messages are private to the implementation

Link: https://github.com/GeneAssembly/biosal/issues/453
Reported-by: Huy Bui <huybui@anl.gov>
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
new parameter -minimum-buffer-size for performance app

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
a memory block with B bytes can allocate B bytes

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
track externally-allocated memory in memory pool

Link: https://github.com/GeneAssembly/biosal/issues/639
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>