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 slotId
	 *            the slot id of the container element
	 * @param content
	 *            the target element to be inserted
	 * @return <code>true</code> if this insertion is valid. Otherwise
	 *         <code>false</code>.
	 */
	protected List checkContent( Module module, DesignElement container,
			int slotId, DesignElement content )
	{
		return new ArrayList( );
	}
	/**
	 * Checks whether elements with the given element definition can be inserted
	 * to the slot <code>slotId</code> in another element
	 * <code>container</code>.
	 * 
	 * @param module
	 *            the module
	 * @param container
	 *            the container element
	 * @param slotId
	 *            the slot id of the container element
	 * @param defn
	 *            the element definition
	 * @return <code>true</code> if this insertion is valid. Otherwise
	 *         <code>false</code>.
	 */
	protected List checkContent( Module module, DesignElement container,
			int slotId, IElementDefn defn )