Create a scss mixin for namespacing pods styles

[nicdford]

Creating a mixin similar to one i've created here would give us the ability to create mixins to use as a namespace prefixers. We could create multiple mixins for different name spacing purposes (pods-core/pods-compat-container/pods-submittable) or create one and pass in a variable for each, whatever would be more convenient for everyone. I'm leaning towards the former as it would reduce the risk of having rogue namespacing names popping up.

Usage would look something like:

@include pods-core-prefix {
 // your styles here
}

Any thoughts?