Merge branch 'map-space-quadtrees'
Conflicts:doomsday/engine/api/doomsday.defdoomsday/engine/portable/src/p_objlink.c
Merge branch 'map-space-quadtrees'
Conflicts:
doomsday/engine/api/doomsday.def
doomsday/engine/portable/src/p_objlink.c