[GRASS5] ps.map changes

[H Bowman]

Hi - I've made some changes to ps.map locally and wanted to give people
a chance to object before I put them in CVS, as they are not bug fixes
per se. I think they make the output look better though.


* grid lines:  place on top of all map layers but below all labels,
tags, text, etc. Currently hidden by filled vector areas.

* floating point legends:  flip them so the biggest value is at the top
and the smallest is at the bottom. Currently looks sort of weird,
especially for elevation or if you have negative values. I didn't do it
as an option as I haven't been able to think of a time when I'd want it
smallest first. Also shorten the tick lines a little bit. Categorical
legends remain smallest value at top.

* text:  default to fontsize 10 if no size is given. Currently it just
"fails" silently with fontsize 0.  I don't think this confuses the
meaning of the size parameter (given in meters), and is a bit handier
than 'comments' for one-liners.

* mapinfo:  add background color/none option. Currently opaque white
block.



regards,
Hamish