[GRASS5] datum shifts

[rgrmill at rt66.com]

You wrote:

> sorry to put another burden on you: to complete the proj update,
> please also add notes in the related HTML pages ([mrsv].proj.html).

Done for [rsv].proj.html.  I have not made changes to m.proj or 
m.proj2.
I'll get to those as my time permits.  Input for those modules are not 
GRASS-specific data types.  There are other tools to perform the same 
function for generic data.

Roger