I installed all of the Plymouth themes from the repo today and set out to try each of them with our new script... I soon found that the unordered list, and a lack of a theme description in the zenity list made it difficult to recall which themes I had already tested!

..because of this I made a few more modifications:
Changelog - Sort themes list alphabetically
- Added theme description to zenity list (as read from theme's .plymouth file)
- Added a check so that if current theme is selected as the new theme, the switch-themes script is not run.
Now if only I could get zenity to display a picture of the theme!
