Remove tray icon when killing program

[jaenicke]

There are a few dirty solutions out in the internet, but no really good solution.

The following method works, but I would not recommend it:
Move the mouse cursor over the tray icons, let the mouse click on the button to expand the tray icons, move the mouse over all icons...
If you do this with your programm, all tray icons are clean then, but for the user it is not really a good solution I think.