saving uncommitted changes in /etc prior to emerge run

logrotate/elog-save-summary

@@ -0,0 +1,10 @@
+# Copyright 1999-2011 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# Rotate the log created by the save_summary elog module.
+
+/var/log/portage/elog/summary.log {
+    su portage portage
+    missingok
+    nocreate
+    delaycompress
+}