Last refactor before CGE 7.0 release: Say hello to TCastleViewport and TCastleWindowB

[DP News-Robot]

This week I finished the last big engine API change before the next release! TCastleSceneManager is now deprecated: instead you should use TCastleViewport to display 3D models. This makes things much simpler, and it allowed me to make TCastleViewport defaults much better. 1. TCastleViewport A simplest working source code demonstrating this (it will compile — …