Update CASA` to work with DGVM, fire, nitrogen, dynpft and crops

We want CASA` to have the same capability that CN now has. That means we need to add a fire and nitrogen cycle models. And we need the ability to run the DGVM (Dynamic Global Vegetation Model), and change land-use with the dynpft option, as well as being able to run the CROP model with it.

Mission Statement:

Couple DGVM, fire, nitrogen, dynpft and crop model to CASA`.

Project Plans/Charter and High Level Information:

• Authority: Gordon Bonan and David Lawrence
• Project Lead: ?
• Scientific Lead: Sam Levis
• Software Engineering Lead: Brian Kauffman

  Design