Use an nonexistent css class for installation warning message, so when

it's installed on the web page it's easy to add the missing class with
a `display: none' so it's not show without any html rehacking.
Disabled the "(installation)" suffix to the main title for now: it's
also used for the window title and that shouldn't have the suffix
because the browser window will have it.

svn: r11452

original commit: bdfcca7d1130c1ecad6aa2e70945bab8c28b6f81

collects/scribble/scribble.css

@@ -502,6 +502,6 @@ i {
   margin: 0em -23em 0em 0em;
   font-size: 82%;
 }
-.author:before { 
+.author:before {
   content: "by ";
-}
+}