Feature/bweir/#79 codas

[briardew]

This should be everything needed for the GEOSana_GridComp for full CoDAS functionality (M2CC, SCREAM products, etc.).

[rtodling]

Here are also some general comments:

1) you need to have RC files that are specific to the trace gases leaving the usual files alone. This applies to anavinfo and to gsi.rc.tmpl

2) we need to talk about adding a test case for trace gases; something that can be run and tested from time to time when changes are made so we can be sure we don't make the mistake of changing your results inadvertently.

3) I believe you edits of GSI_GridComp have changed how GSI handles CO2; also I believe you have changed the units of CO2 w/o regard for other part of the code that might need CO2

4) your settings should be such as to minimize references to the meteorology. I don't think there will be a scenario when an system will use a met + trace gases analysis ... unless I am misunderstanding how the chem part of R21C will run.

5) I swapped GSI_GridComp in your version w/ the default and I get zero diff; sure this breaks your use of the code, but it proves my point that the error is your edits of GSI_GridComp; we should talk about them.

I have a number of other smaller concerns and comments, but the items above make up the most important stuff.

[rtodling]

Brad, just to let you know that I made changes that make the code reproduce the original GSI - the one presently in develop. Notice also, that I changed the follow: 1) placed TGAS rc files in etc/TGAS 2) recovered original rc files (gsi.rc.tmpl and anavinfo) as they are in develop 3) other minor edits I am ready to bring this to develop.

Now what I am doing next - already have it in my sandbox is a setting that runs an O3-only analysis. This will serve as a template for how to run TGAS-only analysis ... we'll need to talk for the latter - I will put those changes in another PR, as I want for this one to go in first.