BUGFIX: Keep ratio on resize

Altered the library so that you can enter a "set" width and height into 'content.json', which will enable the library to calculate the desired ratio between width/height for presentation on a website. Also added a field for minimum width, so that the content author can ensure his/her content will be displayed only at optimal sizes.

The library has been tested, and found working, on all major browsers. Tested OS: Windows 7, OSX 10.9, iOS 7.

Consult the commit diff/message for more information.