Added Magento 1.7 Support

Hi mate,

Absolutely stoked I found your extensions! They're amazing!

I found an issue with this particular extension and Magento 1.7. Only because of how some assets have moved.

I have left your code in tact for Magento 1.6 and less (I'm assuming you have it working in those versions based on your README). I have added a check for Magento 1.7 and fixed the asset loading accordingly.

Please let me know if this isn't suffice and I can make changes.

I am looking at contributing to your projects a lot because I think they're brilliant and I love open source.

PS, what is the specific license you release your extensions with?