las3_pub / predictable_parallel_patterns

The first draft of the internal threading component is currently only implemented using the c++11 std::thread, pthread support will be added next.

For now this is only running our catch tests, but we plan on adding more (ThreadSanitizer, basic performance metrics) later on.

Seperate library from other parts of project (samples, playground, testing, ...). We still are in one 'toplevel' cmake project, so we can for exmaple compile everything (library and playground) in debug mode, for simple development.