Bug 122850 Table/list should not be able to be inserted in Master Page mode.
Description: Table/list should not be able to be inserted in Master Page mode. Steps to reproduce: 1. New a report and transfer to Master Page mode. 2. New a datasource and dataset 3. Drag a list/table to page header/footer, bind it to dataset and drag some columns inside. 4. Save and preview Expected result: Insert list/table item in master page should be forbidden. Actual result: They are allowed and preview showed "undefine" in page
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
Object value = getProperty( module, propName );
		if ( value == null )
			return null;
		if ( value instanceof BigDecimal )
			return (BigDecimal) value;
		ElementPropertyDefn prop = getPropertyDefn( propName );
		PropertyType type = MetaDataDictionary.getInstance( ).getPropertyType(
				prop.getTypeCode( ) );
		return type.toNumber( module, value );
	}
	/**
	 * Applies a design visitor. The derived element calls the corresponding
	 * visitMumble( ) method in the visitor. The visitor allows an algorithm to
	 * be implemented in a single visitor class, rather than all across the
	 * element inheritance hierarchy.
	 * 
	 * @param visitor
	 *            The visitor to apply.
	 */
	public abstract void apply( ElementVisitor visitor );
	/**
	 * Gets a property converted to a string value.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            The name of the property to get.
	 * @return The property value as a string.
	 */
	public String getStringProperty( Module module, String propName )