FORGE-1311 Ensure that UICommands are displayed as wizard steps.

This ensures that UICommands, UIWizards and UIWizardSteps are
displayed in the Eclipse wizard when a collection of UICommands
are returned in the NavigationResult.
Merge pull request #3 from VineetReynolds/FORGE-1311

FORGE-1311 Ensure that UICommands are displayed as wizard steps.
JBIDE-15971: make progress bar visible, crude cancel works for multipage wizards