Add new gradients

- ![image](https://cloud.githubusercontent.com/assets/62244/4140134/9f3dc714-33a1-11e4-9670-ecbeb3a974aa.png) Titanium
- ![image](https://cloud.githubusercontent.com/assets/62244/4140143/ae03da40-33a1-11e4-8a55-7b5ca2193f71.png) Mantle
- ![image](https://cloud.githubusercontent.com/assets/62244/4140155/bee06522-33a1-11e4-99f5-76b4908a59b8.png) Dracula
- ![image](https://cloud.githubusercontent.com/assets/62244/4140126/7c3e486a-33a1-11e4-876f-3f693eaf57cd.png) Peach