Rewrite of addListener to use window.resize rather than creating 'setInterval' for each media query using addListener.
Simplified check when pushing to the queries array
Restructured initial 'if' statement for clarity

This was changed due to feedback by @benschwarz because the '!'(not) operator was easily missed and this method leaves less ambiguity to the intent of this file.
Merge pull request #43 from weblinc/master

Rewrite of addListener to use window.resize rather than setInterval