Undo consolidation of variables with classes.

In @mrmrs' original repository that this gem was based on, the variables were separate from the classes. I think this gem should keep it that way for people who only want to import the variables and not the single-use class names.

They still can bring everything in by just importing the main files, but if they only want variables, they can import the variables file directly. :)

Thanks for making this gem! :)