* Packaging cleanup
Originally I was just trying to remove mentions of snupkg, but then
things got a bit carried away. :)
This is trying to remove as much duplication and dead code related to
packaging that I can.
* Apply code review feedback
* Suppress copying indirect references
* Remove unwanted bundled files from AutoML
* Remove leading slash
* Refactor model download
* Correct the packaging path of native symbols
* Rename NoTargets projects from csproj to proj
* Fix build issues around model download and respond to feedback
* Remove NoTargets file extension enforcement
* Rename proj to CSProj, include in SLN
I'd like to ensure all our projects are included in the SLN and don't
rely on separate build steps.
VS prefers *.csproj in the sln so I renamed things back to csproj.
* Respond to PR feedback