Added candles to line graphs, square data points, and dashed lines

Candles in line graphs

![image](https://cloud.githubusercontent.com/assets/547858/3848976/0de4b4bc-1e75-11e4-8357-49c51f246f10.png)

Square points in radar and line graphs

![image](https://cloud.githubusercontent.com/assets/547858/3848944/ab6b828e-1e74-11e4-8f00-a47f2cd7d282.png)

Dashed lines

![image](https://cloud.githubusercontent.com/assets/547858/3849002/37158cf8-1e75-11e4-8058-87e7f82bf7c5.png)

Made the y offset of the tooltip configurable for a more customizable UI.

![image](https://cloud.githubusercontent.com/assets/547858/3849045/8ef11ca8-1e75-11e4-9aed-ce131dcb555a.png)

![image](https://cloud.githubusercontent.com/assets/547858/3849049/a1f38e76-1e75-11e4-9fda-351b9045a8da.png)

Documented all of the above changes as well :)