Adds media queries support to SC.View

[nicolasbadia]

This PR adds support for a media property which can be defined to views and allows you to define an object where the keys are CSS media queries and the values are a hash of properties to apply.

Example:

    SC.LabelView.extend({
      layout: { left: 20 },
      title: 'Hello World',
      media: {
        '(max-width: 1000px)': { title: 'Hello', layout: { left: 10 } },
        '(max-width: 800px) or (max-height: 500px)': { layout: { left: 5 } }
      }
    })

[nicolasbadia]

Juste updated the implementation to use the same syntaxe as CSS media query. It is now a lot more powerfull.
I believe once it is live, modeAdjust can be deprecated as it adds nothing more...