1) install GMT, download gshhs boundary data and source code
from ftp://ftp.soest.hawaii.edu/pwessel/gshhs/.
2) compile gshhs.c, use to create gshhs_{c,l,i,h}.txt files.
3) run dumpbounds.sh to create states, countries, rivers text files.
4) run readboundaries.py to process into binary files, with metadata in
separate text files.
5) run plotgrdlandmask.py to generate lsmask data.
