Bug 136279 Structure and table datatypes should be hidden.
Description: Structure and table datatype should be hidden. Steps to reproduce: In table data binding, I saw structure and table two datatypes. They are not supported now, so they should be removed.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
* Returns a slot handle to work with the data sets within the report. Note
	 * that the order of the data sets within the slot is unimportant.
	 * 
	 * @return A handle for working with the data sets.
	 */
	public SlotHandle getDataSets( )
	{
		return getSlot( DATA_SET_SLOT );
	}
	/**
	 * Returns a slot handle to work with the data sources within the report.
	 * Note that the order of the data sources within the slot is unimportant.
	 * 
	 * @return A handle for working with the data sources.
	 */
	public SlotHandle getDataSources( )
	{
		return getSlot( DATA_SOURCE_SLOT );
	}
	/**
	 * Returns the default units for the design. These are the units that are
	 * used for dimensions that don't explicitly specify units.
	 * 
	 * @return the default units for the design.
	 * @see org.eclipse.birt.report.model.api.metadata.DimensionValue
	 */
	public String getDefaultUnits( )
	{
		return module.getUnits( );
	}