Fail compilation if the Erlang/OTP system has no dirty scheduler support.
Use `erlang:nif_error/1` to teach the dialyzer to ignore the errors.

Thanks to Anthony Ramine
Fix an error in the timing code.

Luckily this has had no effect on timing in practice save for a small unmeasurable constant factor.

Thanks to the dialyzer for finding the problem.
Improve documentation and write a changelog for 0.10.1

Thanks to David N. Welton.
Hello v0.10.2