Improved widget "Play Until Done" transition

- In the scenario of PUD, after fading content out, instead of fading content back in to show at the top and then triggering "done", trigger "done" immediately
- In `play()` function, adding in a fade-in to ensure the visibility of the `page` content gets revealed if it was previously hidden (which would mean the widget has PUD selected)
Merge pull request #14 from Rise-Vision/chore/pud-transition

Improved widget "Play Until Done" transition