Seperate coupling layer out for the MCT version

Rob Jacobs and Mariana Vertenstein
Use MCT Attribute vectors for all data exchanged between components at the top driver level. Create MCT_xxx_comp.F90 layer for MCT coupling layer for a given component. Converts between MCT and native derived types and calls native xxx_comp.F90 layer init, run and final methods. The ESMF layer xxx_gridcomp.F90 layer matches this same functionality.
Code checked into subversion on cam3_2_46_brnch_mct branch.
Erik responsible to clean this up and move it to cam_dev. This requires changing names, updating branch to latest, and getting SCAM and CCSM to work.
Ideal eng time for this part of the work: 7 days