Use DYNAMIC_ALIGNMENT macro for FastRandom...

Use [`DYNAMIC_ALIGNMENT` macro][1] in `FastRandom::create_aligned` to
construct an aligned `FastRandom` instance.

[1]: http://www.gamasutra.com/view/feature/132367/data_alignment_part_2_objects_on_.php?print=1
Add `fast_random.get_includes()` to reuse headers
Use no Cilk code by default