Show default value as placeholder text

This prevents the issue where deleting the text causes the default value to be enabled thus resetting the text that was just deleted.

![screen shot 2014-04-17 at 11 02 06 am](https://cloud.githubusercontent.com/assets/671378/2734966/6d1ce8e6-c65a-11e3-8b4c-6c5245c60d64.png)

Closes #104