Core/Packet IO: Updated Achievement Achievement Opcocdes and Structures (Temporary achievement fix)

I have here a temporary achievement fix. I did all this work, but it turns out that Sovak also did a lot of it, and Rawaho informed me of it, so I will use it as a reference to finish it out, and do x-realm achieves. 

Some of the guild achievement work is in here, but it's not complete, so don't expect it to be functional at all. The ClientGuildCriteriaUpdate structure is in need of an update for it to work. 

Thanks Sovak and Rawaho for helping me get this done. I hope to contribute more and more as I can.

--Disregard the black market opcodes. I haven't finished working on it.
/slap