target raven support to 4.0 instead of 4.5

StackExchange.Profiling.RavenDb/StackExchange.Profiling.RavenDb.csproj

@@ -9,8 +9,9 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>StackExchange.Profiling.RavenDb</RootNamespace>
     <AssemblyName>StackExchange.Profiling.RavenDb</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -30,11 +31,14 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.CompilerServices.AsyncTargetingPack.Net4">
+      <HintPath>..\packages\Microsoft.CompilerServices.AsyncTargetingPack.1.0.1\lib\net40\Microsoft.CompilerServices.AsyncTargetingPack.Net4.dll</HintPath>
+    </Reference>
     <Reference Include="Raven.Abstractions">
-      <HintPath>..\packages\RavenDB.Client.2.5.2750\lib\net45\Raven.Abstractions.dll</HintPath>
+      <HintPath>..\packages\RavenDB.Client.2.5.2750\lib\net40\Raven.Abstractions.dll</HintPath>
     </Reference>
     <Reference Include="Raven.Client.Lightweight">
-      <HintPath>..\packages\RavenDB.Client.2.5.2750\lib\net45\Raven.Client.Lightweight.dll</HintPath>
+      <HintPath>..\packages\RavenDB.Client.2.5.2750\lib\net40\Raven.Client.Lightweight.dll</HintPath>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.ComponentModel.Composition" />

StackExchange.Profiling.RavenDb/packages.config

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="RavenDB.Client" version="2.5.2750" targetFramework="net45" />
+  <package id="Microsoft.CompilerServices.AsyncTargetingPack" version="1.0.1" targetFramework="net40" />
+  <package id="RavenDB.Client" version="2.5.2750" targetFramework="net40" />
 </packages>

packages/Microsoft.CompilerServices.AsyncTargetingPack.1.0.1/ReadMe.txt

@@ -0,0 +1,12 @@
+IMPORTANT
+
+The "Async Targeting Pack for Visual Studio 11" (Microsoft.CompilerServices.AsyncTargetingPack) has been deprecated.
+It has been replaced by the Microsoft.Bcl.Async NuGet package:
+
+  https://www.nuget.org/packages/Microsoft.Bcl.Async
+
+Since we aren't going to maintain and support Microsoft.CompilerServices.AsyncTargetingPack anymore, we encourage you
+to migrate to Microsoft.Bcl.Async.
+
+Thanks,
+The .NET Framework Team