Add term/label mappings to term panel.

For Issue #1359. The patch adds term/label mappings to term panel.

Original way to show gender distribution if the value is stored as 0 or 1.
![1](https://cloud.githubusercontent.com/assets/517556/3562014/e3fd7862-09db-11e4-9919-f48d204e6b3f.png)

Config term and label mappings 
![3](https://cloud.githubusercontent.com/assets/517556/3562015/e5793604-09db-11e4-9607-03612c8fc734.png)

Convert '0' to 'Female', and '1' to 'Male'
![2](https://cloud.githubusercontent.com/assets/517556/3562016/e67d729a-09db-11e4-9e38-be183221cb55.png)