Bug 19145 [Wizards] Make wizards resizable and keep bounds
Both the Checkbox Tree and the Checkbox List have horizontal scrollbars because mose package names and type names don't fit in the default size. It would be nice to be able to size this dialog bigger, and have it have a wider default size (I assume it is sized for 640x480? but is could be wider).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarPackageWizardPage.java
* @see #createFile
	 */
	protected IFile createFileHandle(IPath filePath) {
		if (filePath.isValidPath(filePath.toString()) && filePath.segmentCount() >= 2)
			return ResourcesPlugin.getWorkspace().getRoot().getFile(filePath);
		else
			return null;
	}
	/**
	 * Set the current input focus to self's destination entry field
 	 */
	protected void giveFocusToDestination() {
		fDestinationNamesCombo.setFocus();
	}
	/* 
	 * Overrides method from WizardExportResourcePage
	 */
	protected void setupBasedOnInitialSelections() {
		Iterator enum= fInitialSelection.iterator();
		while (enum.hasNext()) {
			Object selectedElement= enum.next();
			if (selectedElement instanceof ICompilationUnit || selectedElement instanceof IClassFile || selectedElement instanceof IFile)
				fInputGroup.initialCheckListItem(selectedElement);
			else
				fInputGroup.initialCheckTreeItem(selectedElement);
		}
		
		TreeItem[] items= fInputGroup.getTree().getItems();
		int i= 0;
		while (i < items.length && !items[i].getChecked())