Bug 5571 JAR Packager: Reveal first checked project
If the list of projects in the JAR Packager is long it is possible that the shown projects are not checked even though there are checked projects (due to current selection). ==> reveal the first checked project.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/CheckboxTreeAndListGroup.java
Object[] children= getTreeChildren(treeElement);
		for (int i= 0; i < children.length; ++i)
			determineWhiteCheckedDescendents(children[i]);
		
		if (determineShouldBeWhiteChecked(treeElement))
			setWhiteChecked(treeElement, true);
	}
	/**
	 * Causes the tree viewer to expand all its items
	 */
	public void expandAll() {
		fTreeViewer.expandAll();
	}
	/**
	 *	Answers a flat collection of all of the checked elements in the
	 *	list portion of self
	 *
	 *	@return java.util.Vector
	 */
	public Iterator getAllCheckedListItems() {
		Set result= new HashSet();
		Iterator listCollectionsEnum= fCheckedStateStore.values().iterator();
		while (listCollectionsEnum.hasNext())
			result.addAll((List)listCollectionsEnum.next());
		return result.iterator();
	}
	/**