Changed "Download Firefox" to Standard Download Button


Before and after the changes.
![screenshot from 2014-06-07 13 18 03](https://cloud.githubusercontent.com/assets/1151263/3208072/88bab778-ee18-11e3-8ea4-c20e9e46239d.png)

![screenshot from 2014-06-06 01 23 02](https://cloud.githubusercontent.com/assets/1151263/3208073/8c08da5e-ee18-11e3-94c4-d2576d9d5842.png)