The display names are shown if you add the feed URL, so being able to
distinguish between them is nice.

(Note: I also saw that we had a duplicate ID, so I changed the one we don't
seem to publish anymore)

Similar to PR #12611. This PR implements metadata roundtripping for
tuples used in generic constraints. Completes the generic parameter
constraint work listed in #12347.

* Add support for a new ProjectShimFactory to be consumed by CPS.

1. IProjectShim and IProjectShimFactory are the primary interfaces being introduced that CPS will use to forward project system changes to workspace hosts.
2. Refactored the UpdateOptions code in AbstractRoslynProject and sub-types so that it can be shared with the new project shim.

TODO: Add IVT to CPS binaries to enable consuming these APIs (need to follow up with DavKean)

* Add support for a new ProjectShimFactory to be consumed by CPS

1. IProjectShim and IProjectShimFactory are the primary interfaces being introduced that CPS will use to forward project system changes to workspace hosts.

2. Refactored the UpdateOptions code in AbstractRoslynProject and sub-types so that it can be shared with the new project shim.

3. Add IVT to CPS projects to enable consuming these APIs.

* Fix tests

* Add tests for new CPS project shim.

* Fix the tests and update the Shim factory API to take CommandLineArguments.

* Fix VSI test - VB compilation options must also contain latest parse options

* Some more code refactoring to ensure that for the CPS shim we avoid getting properties through the hierarchy while creating the shim and adding new source files.

* Some more code refactoring to address review feedback:

1. Rename IProjectShim and IProjectShimFactory to IProjectContext and IProjectContextFactory respectively.
2. Add a new sub-type of AbstractProject, namely "AbstractLegacyProject", for legacy C# and VB project system shims. All the Hierarchy accesses for computing properties have been moved to this sub-type.
3. Move legacy project system specific interface implementations (IVsHierarchyEvents, IIntellisenseBuildTarget and ICompilerOptionsHostObject) to AbstractLegacyProject.
4. Merge AbstractRoslynProject into AbstractProject - the only addition in AbstractRoslynProject seem to be support for VsENCRebuildableProjectImpl, which was anyways an optional field.

* Change the name of the flag taken by AddSourceFile to "isInCurrentContext"

* Address review feedback

* Fix tests broken by last commit

* Further cleanup of options setting infrastructure

* Minor refactoring of the Options setting APIs

Everything only needed the IInteractiveWindow. This makes life easier
for TypeScript.

Switch to using TaggedText (from SymbolDisplayPart) for features that want to display classified text.

* Enable building and testing on machines with only Dev15 Preview 3 installed

1. Auto-detect the VS common tools path
2. Convert analyzer samples to import Roslyn targets
3. Ensure dependencies are copied to the output directory
4. Workaround: Use local Microsoft.Net.Compilers.props until we move to a compiler toolset with https://github.com/dotnet/roslyn/commit/05c12ebfcdd08a02dbceded5327a8da7a7df23be
5. Replace references to Microsoft.VisualStudio.ComponentModelHost.dll (VisualStudioReferenceAssemblyVersion) with a nuget reference to RoslynDependencies.Microsoft.VisualStudio.ComponentModelHost
6. Add nuget references to Roslyn.Microsoft.Build, Roslyn.Microsoft.VisualStudio.ExtensionManager, RoslynDependencies.Microsoft.VisualStudio.Diagnostics.PerformanceProvider and RoslynDependencies.Microsoft.VisualStudio.CodeAnalysis.Sdk.UI.

* Remove workaround now that new NuGet packages have been uploaded to nuget.org

* Remove preprocessor directive MSBUILD12 and its references

.. code actions for a refactoring.

.. after merge..

We didn't offer move type to new file if there was a single outer type
in a document with a nested type in it. Move to new file should be
offered for the nested type here.