Emu28 v1.09

DISPLAY.C
- changed function UpdateMainDisplay(), removed DEBUG_DISPLAY
implementation

- bugfix in function UpdateContrast(), used background Color 0 in
calculator off state even if Color 32 was defined, added critical
section for DIB section update because of asynchronous display
update now and added update of annunciators

- bugfix in function CreateLcdBitmap(), DIB section shouldn´t
created from the memory DC

- deleted function WriteToMainDisplay(), not necessary for the new
display implementation any more

- added functions LcdProc(), StartDisplay() and StopDisplay() for
new the implementation of the display engine