Tidying up interfaces to CBSInit and CBSFindInZones.
Documenting assumptions about CBS block allocation used by the arena.
Reinstating exhaustive splay tree search, since a tree or node may intersect a requested zone set, and be larger than a requested size, but still not satisfy a request.
Fixing Res/Bool confusion found by “xc/Debug/fbmtest 244032167”
Implementing allocation in the client arena class.