Fix for code analyzer support on Visual Studio 2017 (fixes #394)

[NightOwl888]

Fixes #394.

This downgrades our code analyzers from .NET Standard 2.0 to .NET Standard 1.3 to fix analyzer loading issues in Visual Studio 2017 when referencing the Lucene.Net NuGet package.

It also downgrades Microsoft.CodeAnalysis.CSharp.Workspaces and Microsoft.CodeAnalysis.VisualBasic.Workspaces to 2.6.1 and adds direct dependencies on Microsoft.CodeAnalysis.CSharp and Microsoft.CodeAnalysis.VisualBasic. There is an unofficial guide that describes how this versioning works, but this should add support for Visual Studio 15.6.1 and higher (previously it was 16.4.0 and higher).

The patch was confirmed to work on Visual Studio 15.9.29 as well as Visual Studio 16.8.2 in both C# and Visual Basic.

A Version.props file was also added so we can manually bump the binary version (version revision only) whenever a change is made, which is a requirement of Visual Studio to be able to reload an analyzer. This will prevent workarounds like #286 (comment) from being necessary, and helps to ensure we are verifying the correct copy when debugging.

NOTE: An attempt was made to detect the Visual Studio version and disable installation of the analyzer using the install.ps1 script, but it turns out that scripting support in NuGet packages is now deprecated and analyzers are now loaded by convention rather than with scripts. The scripts (which even Microsoft's NuGet-packaged analyzers ship with) are only for backward compatibility support with older VS versions and exit early to prevent double-installation from happening when convention-based support exists.

References

• Analyzer NuGet formats
• How to create a Roslyn Analyzer project for C# (unofficial guide to mult-targeting Visual Studio versions)
• xunit.analyzers
• StyleCop.Analyzers
• Tutorial: Write your first analyzer and code fix