Create 256x256 version of the ILSpy icon; and remove the useless 128x128 version from ILSpy.ico (it wasn't getting used).

Note that we are only using the small version as a window icon because WPF on Vista (without updated WIC) crashes when loading 256x256 icons.

ILSpy/ILSpy.csproj

@@ -15,7 +15,7 @@
     <NoStdLib>False</NoStdLib>
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
-    <ApplicationIcon>Images\ILSpy.ico</ApplicationIcon>
+    <ApplicationIcon>Images\ILSpy-Large.ico</ApplicationIcon>
     <RunCodeAnalysis>False</RunCodeAnalysis>
     <StartArguments>/separate</StartArguments>
     <SignAssembly>True</SignAssembly>