Update CHANGES and UPGRADE.txt for 16.16.0

CHANGES

@@ -12,6 +12,24 @@
 ===
 ==============================================================================
 
+------------------------------------------------------------------------------
+--- Functionality changes from Asterisk 16.15.0 to Asterisk 16.16.0 ----------
+------------------------------------------------------------------------------
+
+Core
+------------------
+ * The location where the media cache stores its temporary files
+   is no longer hardcoded to /tmp but can now be configured separately
+   via the astcachedir config variable in asterisk.conf. To retain
+   backwards compatibility, the default location remains /tmp.
+
+app_voicemail
+------------------
+ * The VoiceMail application can now be configured to send greetings and
+   instructions via early media and only answering the channel when it is
+   time for the caller to record their message. This behavior can be
+   activated by passing the new 'e' option to VoiceMail.
+
 ------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 16.13.0 to Asterisk 16.14.0 ----------
 ------------------------------------------------------------------------------

doc/CHANGES-staging/media_cache_cachedir.txt

@@ -1,6 +0,0 @@
-Subject: Core
-
-The location where the media cache stores its temporary files
-is no longer hardcoded to /tmp but can now be configured separately
-via the astcachedir config variable in asterisk.conf. To retain
-backwards compatibility, the default location remains /tmp.

doc/CHANGES-staging/voicemail_early_media.txt

@@ -1,6 +0,0 @@
-Subject: app_voicemail
-
-The VoiceMail application can now be configured to send greetings and
-instructions via early media and only answering the channel when it is
-time for the caller to record their message. This behavior can be
-activated by passing the new 'e' option to VoiceMail.