Change the test-runner program to use Unix sockets.
Change the test-runner program to use Unix sockets.

Since Unix sockets are now the default communication mechanism, the
test-runner program, found in src/tests/run_test.c, should use them
as well.  Otherwise, you have to jump through hoops just to run the
tests.

razr/opentts,razr/opentts,razr/opentts,razr/opentts