Implement ranges::shuffle

[miscco]

This implements the range::shuffle algorithm.

For whatever reason it mt19937 has -at least locally- problems fulfilling the uniform_random_bit_generator<remove_reference<_Urng>> requirement, which is peculiar as it does in the ranges::sample test.

[statementreply]

These comments also apply to ranges::sample. (Apparently the test for ranges::sample didn’t catch this)

[miscco]

Derp, thanks a lot

[miscco]

Merged with #1052