Bug 126288 Show default header and footer heights
The default header and footer heights are 0.5 in. These values should be displayed in the Master page's General properties. Currently, these properties are blank, which is misleading. Also, if I specify 0 for header or footer height, the master page layout should not show the header/footer area.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/layout/MasterPageLayout.java
* 
	 * @param owner
	 */
	public MasterPageLayout( GraphicalEditPart owner )
	{
		super( owner );
	}
	/**
	 * Minimum height for header/footer. TODO:50 is the default value, migrate
	 * it to preference later.
	 */
	public final static int MINIMUM_HEIGHT = 50;
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.draw2d.LayoutManager#layout(org.eclipse.draw2d.IFigure)
	 */
	public void layout( IFigure parent )
	{
		Rectangle parentBounds = getInitSize( );
		Result result = getReportBounds( parentBounds );
		parentBounds = result.reportSize;
		parent.setBounds( parentBounds );
		List children = parent.getChildren( );
		Rectangle clientArea = parent.getClientArea( );
		int y = clientArea.y;
		int height = clientArea.height;
		IFigure figure;
		for ( int i = 0; i < children.size( ); i++ )
		{