Unity level previewer improvements

[MattFiler]

Obviously a lot needs doing to the level previewer in terms of material support, etc. Some important core changes need to be made before those, however:

• Load levels correctly from COMMANDS/MVR, rather than just MVR
• Combine MVR and Commands data
• Load COMMANDS data with names for entities
• Support prefabs in loaded view, with hierarchies
• Option in script editor to show just the selected composite (related to Script Editor Instance Mode #268)
• Option in script editor to select the selected entity (should be relative to loaded composite)
• Option to pull transform data back to selected entity in script editor

[MattFiler]

Exploring the possibility of a nice 3D display within the script editor before taking a look into this ticket. It would be a waaaay nicer solution in terms of keeping things streamlined but I think all the extra functionality the Unity Editor provides is probably gonna be too good to pass up.

[MattFiler]

On the staging branch I've moved the Unity tool over to the latest CathodeLib, and deleted all the old legacy content. I've also re-implemented the Commands loading functionality so that it doesn't pull from MVR (although still can).

I've implemented the ability to load to the selected Composite from the script editor, rather than just loading the whole level, and have improved the general flow for things - e.g. you no longer have to edit the script to change the path to your Alien directory, the script editor will just send that info over.

Next up is a better way of displaying nested composites in the hierarchy. I'm doing it already, but it'd be cool to use the Unity prefab system and then apply alias'd overrides over the top in the proper way.

As well as that, at some point I'll need to find a way to sync all this with current runtime changes in the script editor.

[MattFiler]

Just pushed some more minor material changes. Will look into utilising the correct environment maps next for shiny things.

[MattFiler]

Env maps also implemented.