Adding refunds to Sales by Date report

Create a new axis for "in refunds" on the sales by date report.  Include the refunds in the included time period.  Refunds do not reduce the sales total in the report.

![image](https://cloud.githubusercontent.com/assets/1966834/4486587/b02b1a5e-49e5-11e4-84a7-dedd77a73068.png)