server: Move stuff to rccpp_util.{h,cpp}
server: Move stuff to magic_event_handler.{h,cpp}
doc/whynot: Something about module instances
client/sandbox.lua: Whitelist error()
builtin/voxelworld: Modify client-side initialization to not require call to init()
interface/voxel: VoxelRegistry dirty flag
builtin/voxelworld: Send voxel registry to clients when modified
server: Run modules in separate threads
lua_bindings/mesh: Trigger Urho3D Octree update by using cg->SetZoneMask(magic::DEFAULT_ZONEMASK)