Install config XML schema files with VSIX

[realvizu]

The new VSIX v3 (coming with VS2017) allows installing artifacts to the Visual Studio Schema folder.

• Q1: Shall I drop this feature in the MSI installer or provide it both in VSIX and MSI?
  • Providing two different ways to install a feature can confuse users. Also requires more testing.
• Q2: Shall I drop MSI altogether?
  • Would save dev and test time to drop the WiX installer.
  • On the other hand it means dropping the machine-wide MSBuild integration feature too. Which is both good (pushes users to the recommended nuget way) and bad (there might be some scenarios where machine-wide MSBuild integration is better than per-project?).
• Q3: Unfortunately adding the XML schema to the VSIX requires admin privilege for installing.
  • (A) No problem developers usually have this privilege.
  • (B) Provide two VSIX installers: one with the schemas (admin privilege required) and one without (no admin privilege required). Or one with only the analyzer and one with only the schema?

oh, so many questions...

[realvizu]

A1, A2: Dropped MSI installer.
A3: Config schema support has its own VSIX package.