- Remove World.DependsOn - no longer needed
- Remove Id.AsEntity and .AsPair
- Don't display hex values in .ToString()
- Fix Id.ToString printing "Identifier", not "Id"
- Add a couple of TODO comments
- Rearrange some lines
- Add ReferenceHandle struct,
a wrapper around GCHandle
- Use component hooks to make sure
handles are freed when not used
- Move SpanToRef into Iterator class