allow for increased granularity in warning control

[cognisent]

Following on from my my comments in #903, could we extend the capabilities of Promise.config to accept, in addition to this...

Promise.config({
    warnings: true|false
});

...perhaps something like this...

Promise.config({
    warnings: {
        typeone: true|false,
        typetwo: true|false,
        typethree: true|false
    }
});
// I'll leave the names up to you, if you decide to do this.

I would like to leave Warning: .then() only accepts functions and Warning: a promise was rejected with a non-error turned on, but will generally need to have Warning: a promise was created in a handler but none were returned from it turned off as it happens too frequently (due to external issues).

[cognisent]

Awesome! 👍