RFE: provide a command to display all roles available to a user

[Gene Czarcinski <gene czarc net>]

OK, this got closed on bugzilla with the suggestion to bring it up for 
discussion on the mailing list.

The problem:

Currently, there is no way for a user to display what roles are available ... 
available for switching to via a newrole command.

Solution:

Provide a command to display the roles available to a user ... what roles 
could be specified for that user on a newroles command.

Gene