Add:gui_internal:On-Screen-Keyboard now works partly

[navit-package] / navit / keys.h

#define NAVIT_KEY_LEFT 2
#define NAVIT_KEY_RIGHT 6
#define NAVIT_KEY_BACKSPACE 8
#define NAVIT_KEY_RETURN 13
#define NAVIT_KEY_DOWN 14       
#define NAVIT_KEY_ZOOM_OUT 15
#define NAVIT_KEY_UP 16
#define NAVIT_KEY_ZOOM_IN 17