Removed references to "contingency methods" that were talking about the deleted "emergency" free list allocator.
Documenting ``fastFind`` argument to ``CBSInit``.
Clarifying comment about extra queue element
Deleting some obsolete comment text about callbacks.
Renaming cbsBlockShrink to cbsBlockShrunk and cbsBlockGrow to cbsBlockGrew, since they don't *do* those things, just record that they were done.
Tidying up Find functions, where deletion of emergency code had left some strange double nestings.