Fix for issue3559: No preferences menu in IDLE on OSX

1) Add a comment to the help file to that points to the
   preferences menu.

2) An earlier checkin tried to detect Tk >= 8.10.14,
   but did this in the wrong way. The end result of this
   was that the IDLE->Preferences... menu got surpressed
   when using the system version of Tcl/Tk
diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index 0b6fa61..0f9fb70 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -3,6 +3,8 @@
 
 *Release date: XX-XXX-2008*
 
+- Issue #3549: On MacOS the preferences menu was not present
+
 - Issue #2665: On Windows, an IDLE installation upgraded from an old version
   would not start if a custom theme was defined.