las3_pub / predictable_parallel_patterns

The __thread implementation of thread local, static variables seems more efficient, so we activate this by default. If it is (for some reason) not available/slower than the pthread version, one can toggle it for the specific system/processor later on using macros.

See NOTES.md for details, basically std::thread can use dynamic memory allocation internaly and we want to prevent that.

The local storage per thread is only a pointer, this must be assigned AFTER the local storage object has moved to it's final location (e.g. on the stack of the caller). We might even change this a little further in the future to make the location of the state object more transparent.

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