[GRASS5] features needed for 6.2

[Hamish]

> There already is r.pack/r.unpack in grass wiki add ons written by
> Hamish http://grass.gdf-hannover.de/twiki/bin/view/GRASS/GrassAddOns
> 
> maybe Hamish could submit it to CVS to make it easier for users to  
> find it,


No, it shouldn't go into CVS (as is).

1) it's a quick hack
2) I never finished checking if r.in|out.mat was endian-safe
    (any one with Matlab on a Mac want to try?, turn on g.gisenv debug)
3) Because Matlab stores data column by column instead of row by row
(holdover from FORTRAN I think), the entire map must be loaded into
memory during processing. Not something we want for a non-specialist
module. (I don't want to rotate the map 90deg either)

A better approach might be to create a new mapset dir in the current
location, copy over the WIND file from current mapset and PROJ_* files
from PERMANMENT, switch to the new mapset with g.mapset, 'g.copy @,',
then switch back to the original mapset and .tar.gz the entire temporary
mapset.
?

Personally I don't use this very often so someone else should take it up
if they want it.


Other candiates for inclusion are r.in.wms/r.in.onearth and
v.out.ascii.db. I've never been sure if v.out.ascii.db as the correct
approach or if a C module doing the same (or modification of v.out.ascii
itself) would be better.


Hamish