Bug 174872 Clean up chart model
The chart model contains unused attributes and components. Those just make it difficult to understand the model architecture, so they should be removed from the schema, and the EMF classes must re-generated. Examples are: ChartPreferences, Rule. We need to analyze the model to find out all unused ones. Note that this should not break backward compatibility, otherwise just make them deprecated.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/data/impl/RuleImpl.java
{
		if ( eIsProxy( ) )
			return super.toString( );
		StringBuffer result = new StringBuffer( super.toString( ) );
		result.append( " (type: " ); 
		if ( typeESet )
			result.append( type );
		else
			result.append( "<unset>" ); 
		result.append( ", value: " ); 
		result.append( value );
		result.append( ')' );
		return result.toString( );
	}
	/**
	 * A convenience method provided to create a new initialized rule instance
	 * 
	 * @param rt
	 * @param sValue
	 * @return
	 */
	public static final Rule create( RuleType rt, String sValue )
	{
		final Rule r = DataFactory.eINSTANCE.createRule( );
		r.setType( rt );
		r.setValue( sValue );
		return r;
	}
}