bug#4836: "<S-packet> is undefined" when using AutoHotKey

[Jason Rumney <jasonr@gnu.org>]

  On 31/10/2009 7:36 AM, Glenn Linderman wrote:
> emacs 22.1.1 worked fine with autohotkey.  I have macros for 
> correcting my common typos, and accelerating commonly entered items, 
> and entering characters not found on the keyboard.
>
> Seems none of the autohotkey macros works with emacs 23.1, instead 
> they generate an error "<S-packet> is undefined".

Apparently the "packet" key code is special, so we shouldn't treat it as 
a function key.

I have removed it from the list of function keys that Emacs recognizes, 
so the behaviour should go back to what it was before.  However my 
testing shows that we cannot receive Unicode characters outside the 
current codepage using VK_PACKET as Windows replaces such characters 
with '?' by the time we receive them. It appears that a low level 
keyboard hook may be able to retrieve the original character though, so 
if we receive Lennart's cleaned up keyboard hook patches I'll try to 
look at VK_PACKET support again.