Bug 178164 Use IEngineTask.status constants and remove unnecessary status variables in EngineTask.
1)Remove following redundant variables in EngineTask used for status info. protected final int RUNNING_STATUS_START = 0; protected final int RUNNING_STATUS_RUNNING = 1; protected final int RUNNING_STATUS_STOP = 2; EngineTask already has access to constants declared in IEngineTask. Use those instead. 2)Remove the unused errorHandlingOption in EngineTask.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineTask.java
if ( runnable == null )
		{
			return false;
		}
		
		usingParameterValues( );
		
		return new ParameterVisitor( ) {
			boolean visitScalarParameter( ScalarParameterHandle param,
					Object value )
			{
				return validateScalarParameter( param );
			}
			boolean visitParameterGroup( ParameterGroupHandle group,
					Object value )
			{
				return visitParametersInGroup( group, value );
			}
		}.visit( (ReportDesignHandle) runnable.getDesignHandle( ), null );
	}
	/**
	 * validate whether the parameter value is a valid value for the parameter
	 * 
	 * @param p
	 *            the parameter to be verified
	 * @param paramValue
	 *            the value for the parameter
	 * @return true if the given parameter value is valid; false otherwise
	 */
	private boolean validateScalarParameter( ScalarParameterHandle paramHandle )