thorium: use red-black tree to order multiplexing buffers in a timeline

Link: https://github.com/GeneAssembly/biosal/issues/807
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: add comments for the lazy nature of buffer provisioning

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: remove buffers_with_content (core_set) in multiplexer

Link: https://github.com/GeneAssembly/biosal/issues/813
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
core: add option to enable interleaved keys and values in hash table

Link: https://github.com/GeneAssembly/biosal/issues/812
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
tests: disable assertions on Blue Gene/Q for faster execution

Link: https://github.com/GeneAssembly/biosal/issues/814
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>