Bug 169025 Supports overridden on editor contribution
After contributting a new editor to the multiPageReportEditor, supports to enable the new editor to override a editor by assigning the ID.
UI/org.eclipse.birt.report.designer.ui.editors/src/org/eclipse/birt/report/designer/internal/ui/extension/FormPageDef.java
private int loadPosition( IConfigurationElement element,
			String attributeName )
	{
		String attribute = element.getAttribute( attributeName );
		if ( "left".equals( attribute ) ) 
		{
			return 0;
		}
		else if ( "right".equals( attribute ) ) 
		{
			return 1;
		}
		return 0;
	}
	
	
	
	private String loadStringAttribute( IConfigurationElement element,
			String attributeName )
	{
		return element.getAttribute( attributeName );
	}
	private boolean loadBooleanAttribute( IConfigurationElement element,
			String attributeName )
	{
		String value = element.getAttribute( attributeName );
		if ( value != null )
		{
			return Boolean.valueOf( value ).booleanValue( );
		}