Rewrote PostMessage function according to Jamie's gist

Removed unneeded code
Added forceResize option

Gist: https://gist.github.com/jameymcelveen/6793503
Upped diff to 85 as Firefox was still looping
Merge branch 'jm-dev'
Merge pull request #2 from jmaddington/master

Simplified postMessage, removed unneeded code