Exit after the user's session has finished.  This works around slim's broken
PAM session handling (see
http://developer.berlios.de/bugs/?func=detailbug&bug_id=19102&group_id=2663).

Patch by Eelco Dolstra, from Nixpkgs.

--- slim-1.3.6/app.cpp	2013-10-15 11:02:55.629263422 +0200
+++ slim-1.3.6/app.cpp	2013-10-15 13:00:10.141210784 +0200
@@ -816,7 +822,7 @@
 	StopServer();
 	RemoveLock();
 	while (waitpid(-1, NULL, WNOHANG) > 0); /* Collects all dead childrens */
-	Run();
+	exit(OK_EXIT);
 }
 
 void App::KillAllClients(Bool top) {
