add note about volume adjustments in app_meetme (new sound files are on their way)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6523 65c4cc65-6c06-0410-ace0-fbb531ad65f3

UPGRADE.txt

@@ -160,3 +160,14 @@ chan_modem:
   in this release, and will be removed in the next major Asterisk release.
   Please migrate to chan_misdn for ISDN interfaces; there is no upgrade
   path for aopen and bestdata modem users.
+
+MeetMe:
+
+* The conference application now allows users to increase/decrease their
+speaking volume and listening volume (independently of each other and other
+users); the 'admin' and 'user' menus have changed, and new sound files are
+included with this release. However, if a user calling in over a Zaptel channel
+that does NOT have hardware DTMF detection increases their speaking volume,
+it is likely they will no longer be able to enter/exit the menu or make
+any further adjustments, as the software DTMF detector will not be able to
+recognize the DTMF coming from their device.