Bug 37197 Basepath for relative pathes in JAR-exporter
The basepath for the JAR-exporter is the eclipse-install-directory. I prefer it to be the root of the project (the description is saved in), so that relative pathes end inside the project. Now: <jardesc> <jar path="workspace/projectdir/jar.jar"/> Desired: <jardesc> <jar path="jar.jar"/> Reason: To make the jardesc-files portable for shared projects
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarFileExportOperation.java
*
	 * @param	jarPackages		an array with JAR package data objects
	 * @param	parent			the parent for the dialog,
	 * 			or <code>null</code> if no dialog should be presented
	 */
	public JarFileExportOperation(JarPackageData[] jarPackages, Shell parent) {
		this(parent);
		fJarPackages= jarPackages;
	}
	private JarFileExportOperation(Shell parent) {
		fParentShell= parent;
		fStatus= new MessageMultiStatus(JavaPlugin.getPluginId(), IStatus.OK, "", null); 
		fJavaElementContentProvider= new StandardJavaElementContentProvider();
	}
	protected void addToStatus(CoreException ex) {
		IStatus status= ex.getStatus();
		String message= ex.getLocalizedMessage();
		if (message == null || message.length() < 1) {
			message= JarPackagerMessages.getString("JarFileExportOperation.coreErrorDuringExport"); 
			status= new Status(status.getSeverity(), status.getPlugin(), status.getCode(), message, ex);
		}		
		fStatus.add(status);
	}
	/**
	 * Adds a new info to the list with the passed information.
	 * Normally the export operation continues after a warning.
	 * @param	message		the message
	 * @param	exception	the throwable that caused the warning, or <code>null</code>
	 */
	protected void addInfo(String message, Throwable error) {