Don't swallow all command panel errors as if they were SyntaxErrors

This wasn't our fault. SyntaxError's implementation is weird and so every error ends up being an instance of it. Boo.

src/extensions/command-panel/command-panel.coffee

@@ -81,7 +81,7 @@ class CommandPanel extends View
         else
           @detach()
     catch error
-      if error instanceof SyntaxError
+      if error.name is "SyntaxError"
         @flashError()
         return
       else