some mixin utilities

[bearophile]

Dan:

> https://github.com/patefacio/d-help/blob/master/d-help/opmix/mix.d

> Overcomes this problem:
> writeln( [1: 2] == [1: 2] ); // true
> writeln(S([1: 2]) == S([1: 2])); // false

That will be fixed in the core language.

Bye,
bearophile