Fixed netCDF4 instructions.  Closes #61

Some codes that only used gdal for grid extraction should not have
mentioned compiling the netcdf library.  Some codes that used netcdf
did not mentioned it when they should have.
Merge branch 'issue61' into devel
Swapped out gdal usage, uses netcdf exclusively now.  Closes #68

gdal garbles the image data.  We can use regular expressions to ferret
out the grid metadata that we need.
Merge branch 'issue68' into devel