config grids

The grids used in a CIME-enabled model are all specified in one file: config_grids.xml

There are 3 sections:

"grids" : the full grid name and an alias

"domains" : for each entry in any of the grid longnames there is 1 domain entry describing that grid

"gridmaps" : for each possible combinations of grids that arise in any of the grid long names - there are mapping files that are needed and specified in this section