Bug 142432 MasterPage from library can't be restored to modify
Details: MasterPage from library can't be restored to modify Step: 1.New a library named lib1, and insert a masterpage named lib-mp. 2.Publish the library into resource folder. 3.New a report design and use lib1. 4.Drop the lib-mp from library explorer into outline of report design. 5.Double click lib-mp, and switch to Property editro tab. 6.Click restore. Actual result: Pop up an error message and said that the master page cannot specify size the page type is not custom.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
* 
	 * @param propName
	 *            the name of the property to get. Can be a system-defined or
	 *            user-defined property name.
	 * 
	 * @return the property binding, or null if the overridden value is not set
	 */
	public String getPropertyBinding( String propName )
	{
		PropertyBinding propBinding = module.findPropertyBinding(
				getElement( ), propName );
		if ( propBinding == null )
			return null;
		return propBinding.getValue( );
	}
	/**
	 * Sets the mask of the specified property.
	 * 
	 * @param propName
	 *            the property name to get. Can be a system-defined or
	 *            user-defined property name.
	 * 
	 * @param value
	 *            the overridden value
	 * 
	 * @throws SemanticException
	 *             if the maskValue is not one of the above.
	 */
	public void setPropertyBinding( String propName, String value )
			throws SemanticException