- Better way to track level streaming changes. Fixes race conditions on saving actors during level unstream
- Fix multiplayer games tries to save for both worlds on same actor. Add a client check for world during stream in/out save/load calls.
- Make load game call use seamless travel to prevent clients getting dropped from game
- Make it possible to mark actors as destroyed manually
- Add support for querying streaming load state of levels
- Add cvar to disable spud
- Use non-dynamic multicast delegates instead, we won't do much with blueprint interface and need better performance for callbacks.
- Clean old spud streaming volume stuff from subsystem.
- Add a bool to disable auto level state saving while jumping into another level. Does not play well with multiplayer sessions.
- Do not use handles for world delegate binds, remove all during subsystem uninitialization instead.
- Use "seamless travel start" callback instead for detecting seamless travels, so we won't get notified for transition map travels.

- Remove slot definitions and move them into header
- Make auto travel to level on load optional

- Add build.cs definition to enable ue save system globally
- Fix an issue where spud logs an error while game loaded successfully
- Fix unreal save system path is trying to list external saved files as spud saves

- Remove tick from spud subsystem, not really required for screenshots
- Make auto-travelling to worlds while loading optional

…n error. There might be external save files.

… in level