This is an update to my EXPLAIN XML patch submitted a few days ago.
I've added a documentation patch and modified some of the code per
comments by Gregory Stark.
Because the main consumer of output generated by this patch will
presumably be a machine, I didn't clutter up the documentation with
matching XML output for every standard example query. But, I added
enough to hopefully give the user an idea of what to expect.
Regards,
Tom Raney
