== ToDo ==
* find a real fix  for cos 90 != 0 bug (only in double version of compile)

* get rid of dlabel.h & dlabel.cpp
* use try/throw for errors instead of C-style
* key groups for color configuration need to be rethought
* better to handle keys with "accel" or with "keyPressEvent"?
* It would be nice to press for example "shift" and see, the accel for each button (as a Tooltip or something).
