added helpbrowser to the same class so that Unity properly groups it with the...

added helpbrowser to the same class so that Unity properly groups it with the rest of pd-l2ork windows

pd/src/helpbrowser.tcl

@@ -21,7 +21,7 @@ proc ::helpbrowser::open_helpbrowser {} {
         wm deiconify .help_browser
         raise .help_browser
     } else {
-        toplevel .help_browser -class HelpBrowser
+        toplevel .help_browser -class [winfo class .]
         wm group .help_browser .
         wm transient .help_browser
         wm title .help_browser [_ "Help Browser"]