Upgrade to Foundation 4

I updated the files to foundation 4.1.2 and changed the creation and styling of the `switch` class to `date-switch` to avoid the new Foundation 4 `switch` class. I also updated the example layout to follow the new grid syntax of Foundation 4. I know you mentioned you are looking to go through the code and do some refactoring with this change, but if you want a quick fix here it is. Fixes issue #3.