This action sets the user role of the current user.
http://www.myserver.com/evj/ExtraView/ev_api.action?
user_id=username
&password=password
&statevar=set_role
&user_group=role_id
[&access_token=token_value]
The role_id specified, must exist, else the command will fail.
You can get a list of the valid roles with the command get_roles.
The optional access_token parameter allows you to use a valid OAuth2 token obtained with the get_token command. If you provide the access_token parameter, then the user_id and password parameters should not be provided. This prevents the password being sent in clear text over your network connection.
