Netcode, skill previews: 0.4 update

Following up just in a few days 0.4 release.

- Netcode updates for more stability. Improving bandwidth slightly.
- Skill previews are back and they look even better now!

Everything is available in Sandbox and Online mode. 

I am starting to move from Nakama to W4 Cloud solution, this might take some time. But after it I would be able to support both peer-to-peer and server-authoritative solutions. Look forward to implement that!