Fix buster/build

There will likely be more necessary changes here, like removing commented lines of code.

`buster/compat-0.x.js` basically loads Sinon.JS's IE compatible code, but it actually causes issues in IE8. I've sent a pull request to fix this by wrapping the offending code in it's own closure: https://github.com/cjohansen/Sinon.JS/pull/628.

I spun up an http server and the tests were successful at `http://localhost:8081/doc/samples/strftime.html` in the following browsers I've tested:
* OSX Chrome 39
* OSX Firefox 33
* OSX Safari 6