Add reference assembly project

Ix.NET/Source/Ix.NET.sln

@@ -25,6 +25,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Interactive.Tests",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Interactive.Async.Tests", "System.Interactive.Async.Tests\System.Interactive.Async.Tests.csproj", "{172BD8C4-5C3E-4928-9D3F-746CF336FFEC}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Refs", "Refs", "{A3D72E6E-4ADA-42E0-8B2A-055B1F244281}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Interactive", "refs\System.Interactive\System.Interactive.csproj", "{2EC0C302-B029-4DDB-AC91-000BF11006AD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -55,6 +59,10 @@ Global
 		{172BD8C4-5C3E-4928-9D3F-746CF336FFEC}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{172BD8C4-5C3E-4928-9D3F-746CF336FFEC}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{172BD8C4-5C3E-4928-9D3F-746CF336FFEC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2EC0C302-B029-4DDB-AC91-000BF11006AD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2EC0C302-B029-4DDB-AC91-000BF11006AD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2EC0C302-B029-4DDB-AC91-000BF11006AD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2EC0C302-B029-4DDB-AC91-000BF11006AD}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -62,6 +70,7 @@ Global
 	GlobalSection(NestedProjects) = preSolution
 		{AFD2E6EC-C5B0-4276-A14A-467D786D0DDA} = {87534290-A7A6-47A4-9A3A-D0D21A9AD1D4}
 		{172BD8C4-5C3E-4928-9D3F-746CF336FFEC} = {87534290-A7A6-47A4-9A3A-D0D21A9AD1D4}
+		{2EC0C302-B029-4DDB-AC91-000BF11006AD} = {A3D72E6E-4ADA-42E0-8B2A-055B1F244281}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {9B5F6126-CBBA-4C3A-A3BB-26AFE56DABEC}

Ix.NET/Source/System.Interactive/System.Interactive.csproj

@@ -9,7 +9,8 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\refs\System.Interactive\System.Interactive.csproj" ReferenceOutputAssembly="false" PrivateAssets="all" />
     <EmbeddedResource Include="Properties\System.Interactive.rd.xml" />
   </ItemGroup>
-
+  
 </Project>

Ix.NET/Source/refs/System.Interactive/System.Interactive.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>Interactive Extensions Main Library used to express queries over enumerable sequences.</Description>
+    <AssemblyTitle>Interactive Extensions - Main Library</AssemblyTitle>
+    <Authors>Microsoft</Authors>
+    <TargetFrameworks>net45;netstandard1.0;netstandard2.0</TargetFrameworks>
+    <PackageTags>Ix;Interactive;Extensions;Enumerable</PackageTags>
+    <DefineConstants>$(DefineConstants);REF_ASSM</DefineConstants>
+    <ProduceReferenceAssembly>true</ProduceReferenceAssembly>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\refs\System.Interactive\System.Interactive.csproj" ReferenceOutputAssembly="false" PrivateAssets="all" />
+
+    <Compile Include="..\..\System.Interactive\**\*.cs" Exclude="..\..\System.Interactive\obj\**" />
+  </ItemGroup>
+
+
+</Project>