Hmm... ok, lemme see if I can clean this up a bit. My original inclination with the clean:tl target was that since it's not needed after building is complete (since it gets added to the main hopscotch.js file) that we should just go ahead and clean it out, so /tmp mirrors what you'd end up with in /dist.

We could create a temporary __build directory that always gets destroyed at the end of building? Any temporary files that aren't needed after the build process is complete could go in there.