Remove var usage

[weizman]

the mini version declares one of the variables using var - this is discouraged for many reasons, for example leakage of variables to global object when running in script mode (not module mode)

[weebney]

Interesting. I'm obviously not creating tachyon.min.js by hand, but I do agree it's strange that uglify would do this. Might look into swapping it out for another minifier, but for now it hasn't created any unexpected behavior. As you know, this is only intended to run as a module (at least for now), so I don't know if this is really that big of a deal. Definitely weird, though.