Theme color detection

[Noobsai]

Why is removed detection of background color from user theme in commit ed740bd? In the last version panel is black if custom color is not specified.

[ewlsh]

Three Reasons:

• The theme detection code made the extension more complex and harder to maintain
• A lot of themes are too opinionated for this extension to work
• I've had issues with accessing theme information during unlocking, locking, or suspend led to repeated and unpredictable crashes.

If you would like to theme the shell you can also set a color that matches for now. Alternatively, it is now fairly easy for a theme to add panel transparency.

Long-term I plan to support wallpaper color detection.

[ewlsh]

#116 lays out my future plans.