[Esip-documentation] proposed version of ACDD has been updated

[John Graybeal via Esip-documentation]

As I mentioned a little while ago, I've updated the ACDD 1.3  proposed specification as follows:
- Included the text Alexsandar sent out re geospatial_bounds, geospatial_bounds_crs, and geospatial_bounds_vertical_crs
- Included a number of minor textual improvements based on a recent email from Bob S (I think just to me). I edited some of his suggestions so all errors are mine.

The changes are marked in boldface (deletions in strikethrough).

I have not had a change to review the other recent emails in detail, but will do so now; I may change the text further if there is any conclusion from those emails that seems non-controversial. 

Any other concerns or requests will have to be brought up on the call.

Sorry for the last minute excitement but I think we are in good shape for the discussion.

John