Better cursor readout for NEXRAD hydrometeor classification

Hi all,
Currently, when you do display the new "Hydrometeor Classification" level 3 NEXRAD product and do a "cursor readout" (click the middle mouse button on the display to probe data values), you just get back a numerical value- meaningless to basically everybody.

This adds functionality to replace that numerical value with a string representing the classification (e.g., you see "Light-Moderate Rain" instead of "60").  Screenshot:  
![screen shot 2013-05-30 at 4 31 02 pm](https://f.cloud.github.com/assets/1490630/587848/17057c52-c971-11e2-90d9-7ff2f3ffbd1d.png)

Let me know if you like the idea, or have suggestions for improvements to the implementation.

Thanks!
Mike