Make fetch-thirdparty-deps.ps1 work on more Windows platforms.
Merge pull request #7205 from ScottNZ/nuget

Make fetch-thirdparty-deps.ps1 work on more Windows platforms.
Use travis_retry to reduce the nuget timeout errors.
Merge pull request #7216 from pchote/travis-retry

Use travis_retry to reduce the nuget timeout errors.
Update terrain layer when the terrain data changes.
Introduce ActorPreviewWidget and associated plumbing.
add a Bounds field to IActorPreview
add a World type
modularize the remaining legacy ingame interface widgets

and consolidate chrome root initialization
add an in-game map editor