Update NEWS for 0.8.20

NEWS

@@ -1,4 +1,4 @@
-v0.8.20-head 2016-xx-xx  The Irssi team <staff@irssi.org>
+v0.8.21-head 2016-xx-xx  The Irssi team <staff@irssi.org>
 	* Removed --disable-ipv6
 	* /connect Network now aborts with an error if no servers have been
 	  added to that network.
@@ -17,14 +17,25 @@ v0.8.20-head 2016-xx-xx  The Irssi team <staff@irssi.org>
 	+ autolog_ignore_targets and activity_hide_targets learn a new syntax
 	      tag/* and * to ignore whole networks or everything.
 	+ /hilight got a -matchcase flag to hilight case sensitively (#421).
-	- /squery and /servlist commands have been restored.
-	- Where Irssi would previously only report "System error" on connect,
-	  it will now try harder to retrieve the system error message.
 	- IP addresses are no longer stored when resolve_reverse_lookup is
 	  used.
 	- /names and $[...] now uses utf8 string operations (#40, #411).
 	- Removed broken support for curses.
 
+v0.8.20 2016-09-16  The Irssi team <staff@irssi.org>
+	- Correct the name of an emitted sasl signal (#484)
+	- Correct the prototype for the 'message private' signal (#515)
+	- Corrections in away and hilight help text (#477, #518)
+	- /squery and /servlist commands have been restored.
+	- Where Irssi would previously only report "System error" on connect,
+	  it will now try harder to retrieve the system error message.
+	- Fixed issue with +channels not working properly (#533)
+	- Fixed crash in optchan when item has no server (#485)
+	- Fixed random remote crash in the nicklist handling (#529)
+	- Fixed remote crash due to incorrect bounds checking on
+	  formats, reported by Gabriel Campana and Adrien Guinet from
+	  Quarkslab.
+
 v0.8.19 2016-03-23  The Irssi team <staff@irssi.org>
 	- Fixed regression when joining and parting channels on IRCnet (#435)
 	- Fixed SASL EXTERNAL (#432)