Import C TAP Harness 1.2 as a testing harness

Import C TAP Harness 1.2 as a testing harness

Creates a new top-level tests directory that will be used for all
future automated test code eventually.  Import runtests and the
basic TAP library from C TAP Harness 1.2.  Add top-level check and
test targets that build the full source tree and then the new tests
directory, and then runs runtests on the test list.

Change-Id: I896f8ae488cd1dfa8529a10b4b479e45e7c67afe
Reviewed-on: http://gerrit.openafs.org/2062
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>