Bug 119331 Library - name space terminology and behavior
During BIRT 2.0 library feature review meeting the following change was decided. - Change the term namespace to 'prefix' - By default use the library name as the prefix ( namespace ); the dialog to input prefix should be prompted only if hte auto generated prefix is not unique.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dnd/InsertInLayoutUtil.java
* @return validate result
	 */
	protected static boolean handleValidateParameter( EditPart target )
	{
		return handleValidateParameterDropContainer( target )
				&& DNDUtil.handleValidateTargetCanContainType( target.getModel( ),
						ReportDesignConstants.DATA_ITEM );
	}
	/**
	 * Validates drag source from data view to layout. Support the multiple.
	 * 
	 * @return validate result
	 */
	public static boolean handleValidateInsert( Object insertObj )
	{
		if ( insertObj instanceof Object[] )
		{
			Object[] array = (Object[]) insertObj;
			if(array.length == 0)
			{
				return false;
			}
			for ( int i = 0; i < array.length; i++ )
			{
				if ( !handleValidateInsert( array[i] ) )
					return false;
			}
			return true;
		}
		else if ( insertObj instanceof IStructuredSelection )