gross hack to make things work with HiDPI gtk+

We temporatily set GDK_SCALE to 1 when initializing Gtk+ so that
we get the old non-hidpi behaviour.

src/main.c

@@ -386,6 +386,8 @@ main (int argc, char **argv)
   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
   textdomain (GETTEXT_PACKAGE);
 
+  g_setenv ("GDK_SCALE", "1", TRUE);
+
   ctx = meta_get_option_context ();
   g_option_context_add_main_entries (ctx, gnome_shell_options, GETTEXT_PACKAGE);
   if (!g_option_context_parse (ctx, &argc, &argv, &error))
@@ -435,6 +437,8 @@ main (int argc, char **argv)
 
   _shell_global_init ("session-mode", session_mode, NULL);
 
+  g_unsetenv ("GDK_SCALE");
+
   ecode = meta_run ();
 
   if (g_getenv ("GNOME_SHELL_ENABLE_CLEANUP"))