trying to get the videomode setup right. Now first SDL adds all supported (native) screenmodes, then WinUAE code adds all missing modes. Before this commit, both functions allocated a new memory and so overwrote each others data.
Window Title functions
fill more monitor fields. WinUAE gets those via EnumDisplayDevices
Implement centered texts for gui
added more comments
remove unnused code and TODOs
Finally get rif of gfx.cpp