Rename cbstest.c to fbmtest.c (Free Block Management Test) and generalize it so that it tests both the CBS and Freelist modules.
Split FreelistFind into FreelistFindFirst and FreelistFindLast so that the interface exactly matches the CBS interface.
Fix errors in freelist.c: missing computation of size in FreelistBlockSetLimit; update linked list correct in coalesceRight case in FreelistInsert.
Avoid compiler warnings in freelist.c.
In cbs.c: use $U for Booleans ($B is for bit tables).