[Build] Convert to PCL

Source/SharpVulkan/SharpVulkan.csproj

@@ -9,10 +9,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>SharpVulkan</RootNamespace>
     <AssemblyName>SharpVulkan</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <OutputPath>$(SolutionDir)\Bin\</OutputPath>
-    <TargetFrameworkProfile />
+    <TargetFrameworkProfile>Profile7</TargetFrameworkProfile>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -68,7 +68,7 @@
     <Compile Include="Viewport.cs" />
     <Compile Include="Vulkan.cs" />
   </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\Portable\$(TargetFrameworkVersion)\Microsoft.Portable.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">