Move to Commit 44 of JsViews.
- New documentation topics for JsObservable:
  www.jsviews.com/#jso
- Fix for bug {{else someUndefinedValue}}. See:
  https://github.com/BorisMoore/jsviews/issues/221
- Fix for issue:
  https://github.com/BorisMoore/jsviews/issues/220
- Fixes and improvements for $.observable.observe API
  (See www.jsviews.com/#$observable)
- Minor additional bug fixes and improvements