new string utility to create a comma separated string from list

```
/**
 * Converts a List of String to a comma separated string of characters
 * @param stringList 
 * @return String that is one string built of all elements in stringList separated by ", "
 */
public static String convertListToCommaSeparatedString(List<String> stringList) {
    return StringUtils.join(stringList, ", ");
}
```
