Duplicate selector using enhance-with degrade-from

[pascalduez]

http://sassmeister.com/gist/7197433

We currently make an extensive use of the svg-background mixin for a project.
But I discovered there are a ton of duplicate and noneffective selectors.

This is coming from the fact we use are relying on extending a set of base classes.

It happens when we extend a class with the svg-background inside. Which in turn use the enhance-with and degrade-from mixins.

See gist.

I'm wondering how we could prevent this.

EDIT: Well this is not a Toolkit specific issue actually.