Add $basename variable

lib/autoupdate.ps1

@@ -100,6 +100,7 @@ function get_hash_for_app([String] $app, $config, [String] $version, [String] $u
     $hashfile_url = substitute $config.url @{
         '$url' = (strip_fragment $url);
         '$baseurl' = (strip_filename (strip_fragment $url)).TrimEnd('/')
+        '$basename' = $basename
     }
     $hashfile_url = substitute $hashfile_url $substitutions
     write-host -f yellow $hashfile_url