Recursive includes can cause IntelliSense to be a lot slower

[sean-mcmanus]

With 0.17.0: If your recursive include expands to too many folders, it can cause the red flame (IntelliSense updating) to take too long (e.g. 15 times more include paths can lead to a 5 times slow down). We've disabled recursive includes "by default" for 0.17.0. We have a fix internally, but we're still working on fixing the scenario when new #includes are added.