Fix encodeURIComponent on Ruby 1.8.

Replace .ord with .unpack('U')[0]

lib/gollum/frontend/uri_encode_component.rb

@@ -1,3 +1,4 @@
+# ~*~ encoding: utf-8 ~*~
 =begin
   Copyright 2006-2008 the V8 project authors. All rights reserved.
   Redistribution and use in source and binary forms, with or without
@@ -39,7 +40,8 @@ end
 # define charCodeAt on String
 class String
   def charCodeAt(k)
-    return self[k].ord
+    # 'str'.ord is broken on 1.8
+    return self[k].unpack('U')[0]
   end
 end