Add support in DAP4 for the grid(), geogrind() functions and for the ERDDAP subset-by-value syntax.

[jgallagher59701]

Support these in DAP4:

1. grid()
2. geogrid() - maybe
3. The ERDDAP syntax (e.g., SST[(30.5):(24.6)][(-90.4):(-102.6)])

[ndp-opendap]

To be clear:

Are you talking about implementing what is described on the ERDDAP/GridDap web page?

[jgallagher59701]

To be clear:

Are you talking about implementing what is described on the ERDDAP/GridDap web page?

Yes. But also updating the grid() and geogrid() functions so they work with DAP4. I started on the ERDDAP syntax because I know many people have a hard time with the functions. And, also because I started on that syntax implementation a while ago but dropped it for some reason which I did not document. I now have a pretty good idea why and how I might get it working.