Fix for search input in iOS8

Without a `webkit-appearence: none` and `border-radius: 0`, iOS8 was rendering the input box as a rectangle with circular ends.

Before: 
![screen shot 2014-10-29 at 17 28 22](https://cloud.githubusercontent.com/assets/449004/4830943/33c33854-5f91-11e4-8067-7a7bccefd0a0.png)

After:
![screen shot 2014-10-29 at 17 28 48](https://cloud.githubusercontent.com/assets/449004/4830948/3b35626a-5f91-11e4-99fa-fd32c5081f59.png)