Refactoring of CSS and Jade templates to make the UI more responsive

* Added some media queries to the layout.css script to improve mobile experience
* Structured the index.jade template in a more semantic way
* Changed some DOM element IDs in index.jade and main.js
* Used more of the oundation grid system we have available
Added 1/2 points and ? values to the default point options in settings.js
Fixes a problem sorting the results on reveal

* I forgot to convert the string values into integers, for accurate comparison
* This only became obvious when users voted for points >=10