NIH Enterprises presents: a new testing system based on CuTesT, which is
faster than our previous one and fortunately uses no preprocessing on
the source files, which means we can run that from CMake.

The test suites have been gathered together into bigger files (one file
per suite, testing each of the different submodules of the library).

Signed-off-by: Vicent Marti <tanoku@gmail.com>