[GRASS5] set map title and metadata info using r.support

[Hamish]

Hi,

I've added two options to r.support to let you change the map's title
and add a line of metadata info to the map's hist/ file (viewable with
r.info, r.info -h). They will both run non-interactively from the
command line.

Note that metadata comments are limited to 50 lines of 78 chars each. If
you feed it any more than that it will truncate the input to fit.
Don't count on "$? -ne 0" in the case of the line being too long!

Also represents a new challenge for the folks working on the GUI.. I
guess for now we can live with a terminal that flashes closed just after
launch if non-interactive.

I am looking for a simple bashism to add to the examples section of the
help page for feeding an input file one line at a time into the (looped)
module.


Hamish