Make constelation app URL helpers available to widgets.
Allow ClientServices helpers to provide HTTPS URLs.
Use existing helpers to generate CLS URL.

It would still be better if the CLS could supply this URL so we don't
break things accidentally, but this is better than nothing.
Add secure versions of widget service URL helpers.
Merge pull request #424 from G5/widget-drop-it-like-its-hot

Make constelation app URL helpers available to widgets.