also widened one valgrind suppression to also catch something we
initialize in the assert layer

Newer libc doesn't like _SVID_SOURCE:
https://sourceware.org/ml/libc-alpha/2013-12/msg00652.html

variables with `drd ignore var' and `drd stop ignoring var'

FT-594 add fractal tree version 24 (tokudb 7.0.1) and version 27 (tokudb 7.5.0) stress data directories

bits were inconsistent though the handle was opened without those bits
set. This caused dbremove to always fail.

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.