Separate Makefile targets for tests

[Doug Freed]

Hi,

I'm playing around with a bug in the HPN patch where it deadlocks in
their MT-CTR implementation during the integrity tests, but it's
annoying to have to wait for the entire test suite to finish, which
takes almost 15 minutes on my machine.  It would be nice if each of
the tests had its own target in the Makefile, so I could just issue
something like 'make test-integrity' or whatever to run just that
test, rather than having to wait for the whole suite each time, or
edit the Makefile to only run that test.

Thanks,

Doug Freed