FT-591 fix valgrind uninitialized value error in block allocator test caused by reading past the end of a the blockpair array

FT-273 Prevent setting the memcmp magic on db handles for which a FT is already open. Improve comments. Add a test.

overflow

instead refer to tokuft

one large buffer to serialize a node instead of many smaller ones, which
should hopefully put less pressure on jemalloc during checkpoints etc.

cachefiles, also clean up some formatting.

up report formatting a bit. Also strengthen malformed trace detection.

a running trace (that is, a trace that is still getting written to by some
process)

fragmentation changed

tracing code

ba_replay

create_from_blockpairs would crash the replay. Also fix parsing bugs.

multiple calls), support create_from_blockpairs in the allocator and
trace tool

test