Document that autocompletion is not implemented for wxOSX wxComboBox.

While the relevant methods are in wxTextEntry, they are only really
implemented for wxTextCtrl in wxOSX, not wxComboBox, which also derives from
wxTextEntry.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75000 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/textentry.h

@@ -53,7 +53,8 @@ class wxTextEntry
         single-line text control using the given @a choices.
 
         Notice that currently this function is only implemented in wxGTK2,
-        wxMSW and wxOSX/Cocoa ports and does nothing under the other platforms.
+        wxMSW and wxOSX/Cocoa (for wxTextCtrl only, but not for wxComboBox)
+        ports and does nothing under the other platforms.
 
         @since 2.9.0
 
@@ -81,7 +82,8 @@ class wxTextEntry
         Notice that you need to include @c wx/textcompleter.h in order to
         define your class inheriting from wxTextCompleter.
 
-        Currently this method is only implemented in wxMSW and wxOSX/Cocoa.
+        Currently this method is only implemented in wxMSW and wxOSX/Cocoa (for
+        wxTextCtrl only, but not for wxComboBox).
 
         @since 2.9.2