Bug 122687 Libraries dont appear to allow background colors on tables to be used
If I create a table and set the background color to blue in my library and then drag the table from the library to the report the background color does not go with it.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* 
	 * @param module
	 *            the module
	 * @param propName
	 *            the name of the property
	 * @return <code>true</code> if the property is resolved;
	 *         <code>false</code> otherwise.
	 */
	public boolean checkElementReference( Module module, String propName )
	{
		assert !StringUtil.isBlank( propName );
		
		Object value = propValues.get( propName );
		if ( value == null )
			return true;
		
		ElementPropertyDefn prop = getPropertyDefn( propName );
		assert PropertyType.ELEMENT_REF_TYPE == prop.getTypeCode( );
		
		ElementRefValue ref = resolveElementReference( module, prop );
		return ref.isResolved( );
	}
	/**
	 * Returns the list of elements that extend this one.
	 * 
	 * @return the list of elements. The list is always non-null.
	 */
	public List getDerived( )
	{
		if ( derived != null )