Use html5 date input for CM_FormField_Date?

How's browser support?
Do we need some feature detection to fall back to a different solution depending on support?

![screen shot 2014-06-24 at 09 39 55](https://cloud.githubusercontent.com/assets/360800/3368316/c0a3ff66-fb72-11e3-90fa-512942c99353.png)