[Dibbler] Dibbler for Windows 2000

[Sob]

Hi

I made a patch for Dibbler 0.4.0 allowing it to work on Windows 2000 again. 
Maybe I'm not the only user of Windows 2000 who wants to use DHCPv6, so I 
decided to make it public.

If anyone is interested, it can be found at:

http://web.hisoftware.cz/sob/download/dibbler-0.4.0-win2k.patch.gz

Important notes:

- everything compiles (client, server and relay), but only client is tested 
(= I use it and it works for me)
- compiler used is MinGW, but it may work with others too
- my C programming skills are rather poor, and I'm not really sure about 
all changes I made. It means that it's better to consider this code as a 
starting point for Windows 2000 support, but it's definitely recommended to 
get it verified by someone more skilled.

                                                  Sob