Strong name for designer

src/Windows/Perspex.Designer/Perspex.Designer.csproj

@@ -36,6 +36,12 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
+  <PropertyGroup>
+    <SignAssembly>true</SignAssembly>
+  </PropertyGroup>
+  <PropertyGroup>
+    <AssemblyOriginatorKeyFile>perspex.designer.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
   <ItemGroup>
     <Reference Include="PresentationCore" />
     <Reference Include="PresentationFramework" />
@@ -80,6 +86,7 @@
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
+    <None Include="perspex.designer.snk" />
   </ItemGroup>
   <ItemGroup>
     <Page Include="App.xaml">