Simplest possible sort impl

This ist the simplest possible sort implementation I found (the one in libc++ is too optimized). 
It allows to at least try the sort interface.

Test using default comparison are provided.

TODO:
- test using iterators, custom comparisons, and projections.
- test file needs cleaning.
I would love to write: `for_each(zip(c, generate(p)), [](auto&& i) { std::get<0>(i) = std::get<1>(i); });` but I clashed in the rvalue ref issue again (`for_each` returns an iterator).