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

Lib/idlelib/NEWS.txt

@@ -3,6 +3,8 @@ What's New in IDLE 2.6a3?
 
 *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.
 

Lib/idlelib/help.txt

@@ -90,7 +90,10 @@ Options Menu:
 	Configure IDLE -- Open a configuration dialog.  Fonts, indentation,
                           keybindings, and color themes may be altered.
                           Startup Preferences may be set, and Additional Help
-                          Souces can be specified.
+                          Sources can be specified.
+			  
+			  On MacOS X this menu is not present, use
+			  menu 'IDLE -> Preferences...' instead.
 	---
 	Code Context --	  Open a pane at the top of the edit window which
 			  shows the block context of the section of code

Lib/idlelib/macosxSupport.py

@@ -89,7 +89,9 @@ def overrideRootMenu(root, flist):
 
     ###check if Tk version >= 8.4.14; if so, use hard-coded showprefs binding
     tkversion = root.tk.eval('info patchlevel')
-    if tkversion >= '8.4.14':
+    # Note: we cannot check if the string tkversion >= '8.4.14', because
+    # the string '8.4.7' is greater than the string '8.4.14'.
+    if map(int, tkversion.split('.')) >= (8, 4, 14):
         Bindings.menudefs[0] =  ('application', [
                 ('About IDLE', '<<about-idle>>'),
                 None,