upgrade Dotnet.ProjInfo to v0.31

[enricosada]

• upgrade Dotnet.ProjInfo to v0.31
• drop fsharp.net.sdk projects support

NOTE the Dotnet.ProjInfo v0.31 doesnt create anymore the helper target file in obj dir

[enricosada]

waiting to fix and merge #332 first

[baronfel]

woo let's merge this sucker :D

[baronfel]

Should we report the Mono weekly reflection failure that's failing the tests?

System.NotImplementedException: The method or operation is not implemented.
  at System.Reflection.Emit.AssemblyBuilder.get_ReflectionOnly () [0x00000] in <dfbc4bb8759d4df18fd61c54e0b9082a>:0 
  at Microsoft.FSharp.Reflection.Impl.tryFindCompilationMappingAttributeFromType (System.Type typ) [0x00012] in <5b02f7c8dff9fae1a7450383c8f7025b>:0 
  at Microsoft.FSharp.Reflection.Impl.tryFindSourceConstructFlagsOfType (System.Type typ) [0x00000] in <5b02f7c8dff9fae1a7450383c8f7025b>:0 
  at Microsoft.FSharp.Reflection.Impl.isExceptionRepr (System.Type typ, System.Reflection.BindingFlags bindingFlags) [0x00000] in <5b02f7c8dff9fae1a7450383c8f7025b>:0 
  at Microsoft.FSharp.Reflection.Impl.getTypeOfReprType (System.Type typ, System.Reflection.BindingFlags bindingFlags) [0x00000] in <5b02f7c8dff9fae1a7450383c8f7025b>:0 
  at Microsoft.FSharp.Reflection.FSharpType.IsUnion (System.Type typ, Microsoft.FSharp.Core.FSharpOption`1[T] bindingFlags) [0x00026] in <5b02f7c8dff9fae1a7450383c8f7025b>:0 
  at (wrapper dynamic-method) Microsoft.FSharp.Reflection.FSharpType.Boolean IsUnion(System.Type, Microsoft.FSharp.Core.FSharpOption`1[System.Reflection.BindingFlags])(object,object[])

It'd be kinda bad if FSharpType.IsUnion and friends wouldn't be able to run in FSI.

[baronfel]

https://github.com/mono/mono/blob/master/mcs/class/corlib/System.Reflection.Emit/AssemblyBuilder.cs#L405-L408 seems like the member is just not implemented :-/

[baronfel]

I raised an issue at mono/mono#13028 to discuss the NotImplementedException