add helper methods for grouper client

For example:

/**

• see if a user has a privilege on a group
• @param groupName
• @param sourceId
• @param subjectId
• @param privilege
• @return true if has privilege
  */
  public static boolean hasPrivilege(String groupName, String sourceId, String subjectId, String privilege) {
  GcGetGrouperPrivilegesLite gcGetGrouperPrivilegesLite = new GcGetGrouperPrivilegesLite().assignGroupName(groupName);
  gcGetGrouperPrivilegesLite.assignSubjectLookup(new WsSubjectLookup(subjectId, sourceId, null));
  gcGetGrouperPrivilegesLite.assignPrivilegeName(privilege);
  WsGetGrouperPrivilegesLiteResult wsGetGrouperPrivilegesLiteResult = gcGetGrouperPrivilegesLite.execute();
  WsGrouperPrivilegeResult[] wsGrouperPrivilegeResults = wsGetGrouperPrivilegesLiteResult.getPrivilegeResults();
  if (GrouperUtil.length(wsGrouperPrivilegeResults) == 0) { return false; }

return StringUtils.equals("T", wsGrouperPrivilegeResults[0].getAllowed());

}