Michael: Thanks for the tip about how the UI components work. I was able to put a Done button inline and it looks better now.

I've attached an update (v.0.2.3) with the following changes:
- Now displaying a "Done" button to close the panel instead of "Cancel".
- View Manager now checks if the 3DM file has been saved before activating so that it knows where to save the "filename.views.json" file which is saved alongside the 3DM file and contains the view settings.