Using CSS classes instead of inline styling to fix icons with input-group.

To fix the icons for input groups, inline styling was being used on the icon. This worked fine as long as I used the form-horizontal class on my forms. However, for regular forms this didn't work and the inline styling made it harder to override the styling to get it to work.

Here is an example of what I was getting before:
![icon_group_error](https://cloud.githubusercontent.com/assets/5718063/3702484/feec34d2-13ff-11e4-9082-f09330e65b01.jpg)

I removed the inline styling and adding CSS classes to do the styling. Now you can override this styling much more easily and won't have to use the !important which isn't really good practice.

So now I get the following with some easier custom styling:
![icon_group_fixed](https://cloud.githubusercontent.com/assets/5718063/3702560/c9edbc0a-1400-11e4-9177-cb649da49914.jpg)

I added two new demos, date2.html and regular.html. date2.html is the demo from the screenshots. regular.html is a demo for regular form instead of a form-horizontal form since there is a lack of regular form demos.