Bug 206093 bar chart: title of y axis is not aligned according to the y axe.
Build ID: v20070924-0630 Steps To Reproduce: 1. Create a bar chart 2. For y axis enter a Title and set the alignment to center 3. See the chart, the y axis title is not aligned according to the y axe; it is center aligned with the height of the chart. More information: see attached chart image example: the first image at the top is how Birt aligned the y axis label and the second image at the bottom is the proposition of aligment according to the y axe
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/AxesRenderHelper.java
* 
		 * @param i
		 *            tick index
		 * @throws ChartException
		 */
		void handlePreEachTick( int i ) throws ChartException;
		/**
		 * Handles computation after rendering each axes tick
		 * 
		 * @param i
		 *            tick index
		 * @throws ChartException
		 */
		void handlePostEachTick( int i ) throws ChartException;
	}
	private final class TextAxisTypeComputation implements IAxisTypeComputation
	{
		ComputationContext context;
		ITextMetrics itmText;
		int iDateTimeUnit;
		TextAxisTypeComputation( ComputationContext context )
		{
			this.context = context;
		}
		public void initialize( ) throws ChartException
		{
			iDateTimeUnit = ( sc.getType( ) == IConstants.DATE_TIME ) ? CDateTime.computeUnit( sc.getData( ) )
					: IConstants.UNDEFINED;
			itmText = xs.getTextMetrics( la );
			sc.getData( ).reset( );