NuGet package has incorrect layout

[amis92]

Currently analyzer dll is put into lib/portable-..., should be int analyzers/dotnet/cs

Requires fixing package build - possibly solved using VS2017 SDK-style csproj with built-in nuget pack.

[amis92]

When moving to SDK-style csproj with nuget pack suport, there are few issues:

1. DevelopmentDependency needs to be specified, it's fixed but not released yet: netcore projects don't support setting as developmentDependency NuGet/Home#4694

2. dlls need to be put in analyzers/dotnet/cs - to achieve that we have to set <BuildOutputFolder>True</BuilOutputFolder>, as well as <IsTool>True</IsTool> - the second one stops pack from nesting dlls in {targetFramework} folders.

3. Remove dependency on .NET Standard Library -probably. Needs testing and also maybe it would work if target framework was set to net451/452? If not, patching generated nuspec would be needed, possibly with inspiration from https://github.com/m0sa/NuGet.FrameworkAssemblyPacker which works around Framework assemblies are no longer added to .nuspec when using the new .csproj project system NuGet/Home#4853

[amis92]

Closed by c640ea7