cromp packet structural changes

[Fred T. Hamster]

cromp needs a typing system. one byte for 253 or 254 options on types, and then l
ike FF can mean second byte has more info.

this makes a lot of our type packing nicer.

---

change the cromp name being in the package. need more subtle ways to know it's a
good package.

need a checksum field, which can optionally be zeroed and ignored, or omitted, or
whatever.

---

rest on the assertion that cromp packets are always "clear" (not encoded)
as far as headers and meta data.

data content inside packet can be arbitrarily structured, encrypted, whatever.

---

need to not define any service as having contents that are clear text contents?
hmmm. no. we always have the cromp encryption stuff as an option for the data, don't we?
or we should at least.

---

make encryption THE DEFAULT for cromp services.
nothing in data contents should ever be visible, unless they explicitly and probably
stupidly want that.

=========

update the cromp protocol document with these new ideas.