getSuggestions CommandArgs parameter

It would be very useful to have the parameter CommandArgs to method getSuggestions in Provider class.

Example:

``` java
/**
* Get a list of suggestions for the given parameter and user arguments.
*
*

If no suggestions could be enumerated, an empty list should
* be returned.

*
* @param arguments The arguments
* @param prefix What the user has typed so far (may be an empty string)
* @return A list of suggestions
*/
List getSuggestions(CommandArgs arguments, String prefix);
```