added required icon for feedback icons

Added the option to have a require icon display prior to user interaction to show what fields are required.
This is useful for people that only use Labels for screen readers only, therefore taking advantage of the placeholder attr. for design purposes.

These changes can be viewed and tested in the demo/feedbackicons.html

Please review my code let let me know if there is anything I need to change. 
@AlaskanShade Thanks. That's what I thought! Anyway, I don't want to hardcode the ```notEmpty``` here.
Maybe I will use the ```required``` attribute.