cromp -- add cromp version field

[Fred T. Hamster]

version for cromp

1. must have version in cromp but it might be too fat already...?
2. isn't there a way to compress how cromp does its packing and headers and stuff?
3. we want a version in there, but we don't want to add a ton of new stuff.
4. would be good to have a way of distinguishing protocol versions for cromp clients / servers.
5. can this be a simple byte/long exchanged at beginning of connection?
6. it is important to add a version number to cromp; how about in the login stuff?