video fixes, unplugged style changes

Video modal - the bottom border was clipped again after the recent addition of the download button.  I've reordered the code to make it more logical, but the fundamental problems is that the image of the button is added with height:auto and the browser doesn't do re-layout immediately and the image is taller than the tabs.  So I've specified the height of the image to match the actual PNG file.  Then I set negative margins above and below so that the height ends up being the same as the tabs.

I also moved the dialog.show() to the bottom of the function.  this way, our users don't have to watch as we both resize and re-center the dialog on screen.  Now, this all happens before it appears on screen.

Minor still changes to the unplugged levels.  Buttons are renamed, reordered, and restyled per discussion (and approval) from Katie.