[GRASS5] m.proj2 updates

[Hamish]

Hi -

I've just made some changes to m.proj2 which I think will make it a lot
more useful as a frontend to cs2cs from within GRASS.


* data output is now sent to stdout (when appropriate). This means you
  can easily use it in a script. (all other messages go to stderr)

e.g.  ANSWER=`echo "$LON $LAT" | m.proj2 inproj="..." outproj="..."`


* added -i flag to use WGS84 as input and current location as output
  projection.

* added -o flag to use current location as input and WGS84 as output
  projection.

e.g.  ANSWER=`echo "$LON $LAT" | m.proj2 -i`

Using the current projection info allows m.proj2 to use +towgs84=,, params
etc., which got stuck in the parser before.


I still don't fully understand all the projection library stuff, so if
someone could please check...?  The WebCVS does a lot better than 
'diff -u' for the changes:
http://freegis.org/cgi-bin/viewcvs.cgi/grass/src/misc/m.proj2/main.c.diff?r1=1.8&r2=1.10


Interactive mode and LL->LL datum shifts still need a bit of work by
someone.



enjoy,
Hamish