Restore old setupIcon flag

This makes icon and setupIcon just aliases to the same variable

src/Update/Program.cs

@@ -117,7 +117,8 @@ int executeCommandLine(string[] args)
                     { "p=|packagesDir=", "Path to the NuGet Packages directory for C# apps", v => packagesDir = v},
                     { "bootstrapperExe=", "Path to the Setup.exe to use as a template", v => bootstrapperExe = v},
                     { "g=|loadingGif=", "Path to an animated GIF to be displayed during installation", v => backgroundGif = v},
-                    { "i=|icon", "Path to an ICO file that will be used for the Setup executable's icon", v => setupIcon = v},
+                    { "i=|icon", "Path to an ICO file that will be used for icon shortcuts", v => setupIcon = v},
+                    { "setupIcon", "Path to an ICO file that will be used for the Setup executable's icon", v => setupIcon = v},
                     { "n=|signWithParams=", "Sign the installer via SignTool.exe with the parameters given", v => signingParameters = v},
                     { "s|silent", "Silent install", _ => silentInstall = true},
                     { "b=|baseUrl=", "Provides a base URL to prefix the RELEASES file packages with", v => baseUrl = v, true},