Reacting to System.Collections.Concurrent versioning change
Use non-recursive copy operation to fix path too long exception during "kpm pack"
Revert "Reacting to System.Collections.Concurrent versioning change"

This reverts commit d142dad157a131702b767094c2230ee92c1019b8.
Not exclude project root when "kpm pack" with project root as wwwroot
Use the DTH runtime framework to get the correct AssemblyLoadContextFactory.
Add some caching so that the common case only does the work once