Bug 122850 Table/list should not be able to be inserted in Master Page mode.
Description: Table/list should not be able to be inserted in Master Page mode. Steps to reproduce: 1. New a report and transfer to Master Page mode. 2. New a datasource and dataset 3. Drag a list/table to page header/footer, bind it to dataset and drag some columns inside. 4. Save and preview Expected result: Insert list/table item in master page should be forbidden. Actual result: They are allowed and preview showed "undefine" in page
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* 
	 * @return list of libraries.
	 */
	public List getLibraries( )
	{
		return getLibraries( IModuleNameSpace.ONE_LEVEL );
	}
	/**
	 * Inserts the library to the given position.
	 * 
	 * @param library
	 *            the library to insert
	 * @param posn
	 *            at which the given library is inserted.
	 */
	public void insertLibrary( Library library, int posn )
	{
		if ( libraries == null )
			libraries = new ArrayList( );
		
		assert posn >= 0 && posn <= libraries.size( );
		libraries.add( posn, library );
	}
	/**
	 * Adds the given libray to library list.
	 * 
	 * @param library
	 *            the library to insert
	 */
	public void addLibrary( Library library )