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
{
		return getElement( ).getFloatProperty( module, propName );
	}
	/**
	 * Returns the value of a property as a number (BigDecimal).
	 * 
	 * @param propName
	 *            the name of the property.
	 * @return the value as a number. Returns <code>null</code> if the value
	 *         cannot be converted to a number.
	 */
	public BigDecimal getNumberProperty( String propName )
	{
		return getElement( ).getNumberProperty( module, propName );
	}
	/**
	 * Returns a handle to work with a Dimension property. Returns null if the
	 * given property is not defined or not dimension property.
	 * 
	 * @param propName
	 *            name of the property.
	 * @return a corresponding DimensionHandle to deal with the dimension
	 *         property. Return <code>null</code> if the property is defined
	 *         or not dimension property.
	 * 
	 * @see DimensionHandle
	 */
	public DimensionHandle getDimensionProperty( String propName )
	{
		ElementPropertyDefn propDefn = getElement( ).getPropertyDefn( propName );