Merge branch 'remove-polyobjects' into 'next'

src/doomdef.h

src/hardware/hw_bsp.c

src/hardware/hw_main.c

src/lua_blockmaplib.c

src/p_map.c

src/p_maputl.c

src/p_mobj.c

src/p_polyobj.c

src/p_polyobj.h

src/p_saveg.c

src/p_setup.c

src/p_sight.c

src/p_spec.c

src/p_user.c

src/r_bsp.c

src/r_bsp.h

src/r_defs.h

src/r_plane.c

src/r_plane.h

src/r_segs.c