As per the discussion at https://github.com/google/capsicum-test/pull/26, there's some things that maybe needn't get imported here:
- Anything under ./casper/ (which includes the gtest-1.6.0 copy), because FreeBSD is already the up-to-date source-of-truth for Casper related code
- Anything under ./libcaprights/, because it's entirely Linux-specific.
(Also: is there a pre-existing version of gtest-1.8.1 that could make the version here superfluous?)