Split out build targets into all (only libraries) and tests (only
tests). The original Makefile built only the tests.
This solves a problem with (only slightly) older versions of FreeBSD
which don't have libpthreads. This is required for the tests, and
since there are other issues, it doesn't seem to be worthwhile trying
to fix them. If you want to build the tests on a release older than
5.3, you'll have to play around a bit.
New port: ptmalloc is an older version of the GNU libc malloc. It has
a BSD compatible license and outperforms FreeBSD's malloc by an order
of magnitude with some pathological files (notably pthreads and
realloc abuse).