added 2 functions:
added 2 functions:

def list_users_in_role(role):
    """List all users of a given role (see table accROLE)
       @param role: role of user (string)
       @return list of uids"""

def list_users_in_roles(role_list):
    """List all users of given roles (see table accROLE)
       @param role_list: list of roles [string]
       @return list of uids"""

tiborsimko/invenio,tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio