put DebugType into csproj to work around https://github.com/Microsoft/msbuild/issues/2754

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

@@ -5,6 +5,7 @@
     <AssemblyTitle>Interactive Extensions - Async Providers Library</AssemblyTitle>
     <TargetFrameworks>net45;netstandard1.0</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable;Asynchronous</PackageTags>
+    <DebugType>embedded</DebugType>
   </PropertyGroup>
 
   <ItemGroup>

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

@@ -5,6 +5,7 @@
     <AssemblyTitle>Interactive Extensions - Async Library</AssemblyTitle>
     <TargetFrameworks>net45;net46;netstandard1.0;netstandard1.3</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable;Asynchronous</PackageTags>
+    <DebugType>embedded</DebugType>
   </PropertyGroup>
 
   <ItemGroup>

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

@@ -5,6 +5,7 @@
     <AssemblyTitle>Interactive Extensions - Providers Library</AssemblyTitle>
     <TargetFrameworks>net45;netstandard1.0</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable</PackageTags>
+    <DebugType>embedded</DebugType>
   </PropertyGroup>
 
   <ItemGroup>

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

@@ -6,6 +6,7 @@
     <Authors>Microsoft</Authors>
     <TargetFrameworks>net45;netstandard1.0</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable</PackageTags>
+    <DebugType>embedded</DebugType>
   </PropertyGroup>
 
   <ItemGroup>