fixed confusion between width and height
added command line option to select sdl or dlo output
updated usage of defines in sample applications
droppen argc/argv in sdltest.c
new features and fixes for semihost library

- added defines for display configuration
- implemented enable display register bit
- prepared scan direction inversion
  already implemented in dlo output, sdl implementation missing
- implemented pixel format conversion for dlo output module, does not yet work correctly