Bug 128586 Change parameter in drill through link doesn't work in pdf.
Description: Change parameter in drill through link doesn't work in pdf. Steps to reproduce: 1. New a report source and a report target. 2. Insert a report parameter p1 in target.rptdesign, drag it to Layout. 3. Insert a label in source.rptdesign, define a drill through link to target.rptdesign and set p1 to "first". 4. Preview source.rptdesign in pdf and click the link. 5. Revise drill through link to set p1 to "second", then preview in pdf, click the link. Expected result: Target show "second" as value. Actual result: Target still showed "first"
engine/org.eclipse.birt.report.engine.emitter.pdf/src/org/eclipse/birt/report/engine/emitter/pdf/PDFEmitter.java
* @param endY 				the end Y coordinate of the line
	 * @param width 			the lineWidth
	 * @param color 			the color of the line
	 * @param lineStyle 		the given line style
	 * @param contentByte 		the given pdf layer
	 */
	private void drawLine(float startX, float startY, float endX, float endY, float width, 
			Color color, String lineStyle, PdfContentByte contentByte )
	{
		 
		
		if (null == color || 0f == width || "none".equalsIgnoreCase(lineStyle)) 
		{
			return;
		}
		contentByte.saveState();
		if ("solid".equalsIgnoreCase(lineStyle)) 
		{
			drawRawLine(startX, startY, endX, endY, width, color, contentByte);
		}
		if ("dashed".equalsIgnoreCase(lineStyle)) 
		{
			contentByte.setLineDash(3*width, 2*width, 0f);
			drawRawLine(startX, startY, endX, endY, width, color, contentByte);
		}
		else if ("dotted".equalsIgnoreCase(lineStyle)) 
		{
			contentByte.setLineDash(width, width, 0f);
			drawRawLine(startX, startY, endX, endY, width, color, contentByte);
		}