Refactor renderer switching

src/android/i_video.c

src/console.c

src/console.h

src/d_main.c

src/dummy/i_video.c

src/hardware/hw_cache.c

src/hardware/hw_glob.h

src/hardware/hw_main.c

src/hardware/hw_main.h

src/hardware/hw_md2.c

src/i_video.h

src/m_menu.c

src/p_setup.c

src/p_setup.h

src/r_data.c

src/r_main.c

src/r_main.h

src/screen.c

src/screen.h

src/sdl/i_video.c