Add CMake configuration for test/googletest and test/unit

For CMake builds, latest googletest 1.8.0 is downloaded.

Following officially recommended integration for CMake-enabled projects
https://github.com/google/googletest/blob/master/googletest/README.md

  "Use CMake to download GoogleTest as part of the build's configure step.
  This is just a little more complex, but doesn't have the limitations
  of the other methods."

Since, our copy of test/googletest
- is a very minimalist copy of googletest
- does not include any official CMake scripts
- would require copying parts of googletest CMakeLists.txt, compilater/linker flags (e.g. -lpthreads)
for reliable multi-platform builds, it is reasoanable to rely on download
All pros and cons advantages are discussed in teh README.md linked above.

Closes #1033

0 files changed, 0 insertions, 0 deletions