Initial steps changing to SDL 2.0
Merge branch 'master' into sdl-2.0
working through the migration guide https://wiki.libsdl.org/MigrationGuide
Reformat with KDevelop to correct indentation.
Replace SDL_ACTIVEEVENT by SDL_WINDOWEVENT enter/leave.
Replace SDLKey --> SDL_Keycode
Replace #include <SDL/foo.h> by <foo.h>.
SDL_CreateThread() now requires a thread name.  SDL_KillThread() is removed; need to add a "stop" flag to the thread function .
Remove call to SDL_SetColorKey() because the pixel format no longer has a transparent color value.
SDL 2.0 no longer supplies fswindow nor wmwindow in SDL_SysWMinfo.
More fixes
Replace void* m_state by member m_ttf_font carrying the actual type.
Replace void* m_state by SDL_Surface* m_surface.
Merge branch 'master' into sdl-2.0
More piecemeal conversion.
Now compiles.  Doesn't run properly.
It runs!!