In C++17 mode, libc++'s `std::shuffle` isn't compatible with Boost's random
generators because the `min` and `max` functions aren't `constexpr`, so use
`std::mt19937` instead. This might not be required if boostorg/random#24 is
accepted.
The C++ standard deprecates use of <stdio.h>, <stdlib.h> etc., and suggests using <cstdio>, <cstdlib> etc.
Some trailing whitespace removed in affected files because of a setting in my editor
dead code surrounded by #if 0 ... #endif removed
