[Grace-core] Four "notes" on Grace: potential blog posts

[James Noble]

Hi all

so on the plane back I typed up four notes on Grace
I've now put these onto the wiki page.

Once we're all happy with them, I think we should dribble them out
to the blog, one or two every week or so (or perhaps once discussion
on one dries down, send the next).

I did some in advance so I wouldn't have to do much in the next
two weeks, when I'll be marking pretty flat out.

Three of 'em are mostly OK, the one on messages is too long
and should probalby be chopped in half.

The BNF everywhere is wrong, but it's a start!

J