Description of problem:
If the panel background is changed the applets should follow as well (and paint
their backgrounds using panel->getBgColor(), or whatever function the panel has
for interfacing with other components), making the panel and it's applets look
more consistent.

Version-Release number of selected component (if applicable):
2.2.0-3

Additional info:
To ensure that text components (such as the clock) does not get hard to read if
the panel background is f.eg. dark green, I believe it would be a good idea for
the applets with text labels to average the pixels in the desktop background
that lies behind the applet, and draw the text in white if
(background_average_value < 128) and black if (background_average_value >= 128).