[Dart-dev] updates to wrf files in dart repository

[Nancy Collins]

hi wrf-dart users,

i've committed several minor updates to wrf related files in the
dart subversion repository.   the details are:

- use >! and >>! in the advance_model.csh script so that if
you use c-shell and have noclobber set (so the shell won't
overwrite existing files), the model advance won't fail mysteriously.

- add the 'allow_obs_below_vol' namelist item to a couple of
the wrf utility programs since they share the model_mod namelist.

- fix the local/private key numbering code in the radar obs_def file,
so you can generate test radar observations with 'create_obs_sequence'.

thanks to soyoung for finding (and in most cases fixing) these
problems.

nancy