[Dart-users] update to WRF model_mod and utils

[Nancy Collins]

dear dart users,

i've committed an updated WRF model_mod.f90 from josh hacker that
should be fully backwards compatible, but includes support for
the single column model configuration of WRF.   the update includes
new code in model_mod.f90 to handle the wrap-around in both the
x and y directions,  model_mod.nml which includes 2 new namelist items
(periodic_y and scm, both logicals which default to .false. ).  i've also
updated the two utility programs that share the model_mod namelist
(dart_tf_wrf.f90 and ensemble_init.f90).

last week i also committed updates from ryan torn which remove the
fixed tables for microphysics schemes and simply read the input netcdf
file and convert all fields found there into the state vector.  those 
programs
include pert_wrf_bc.f90 and update_wrf_bc.f90, and a utility routine
in module_netcdf_interface.f90.   this update means there is no dependence
on the WRF namelist.input namelist, and that as new microphysics schemes
are added these programs will not need to be updated.  it also means that
they can handle ensembles with different microphysics schemes, only
updating the variables which exist.

if you have any questions, please let me know.
nancy