Change default lease time for DHCPv6 to one day.

Also remove floor on valid and preffered times in RA when
no time is specified.
diff --git a/CHANGELOG b/CHANGELOG
index b76c75e..4b4e5b3 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -10,6 +10,14 @@
 	Fix crash under heavy TCP connection load introdcued in 2.81.
 	Thanks to Frank for good work chasing this down.
 
+	Change default lease time for DHCPv6 to one day.
+
+	Alter calculation of preffered and valid times in router
+	advertisements, so that these do not have a floor applied
+	of the lease time in the dhcp-range if this is not explicitly
+	specified and is merely the default.
+	Thanks to Martin-Éric Racine for suggestions on this.
+
 	
 version 2.81
 	Improve cache behaviour for TCP connections. For ease of