Code improvement for read_met_module and write_met_module: now, rather than

Code improvement for read_met_module and write_met_module: now, rather than
calling these read and write routines with a load of arguments, which must
be declared individually in the calling subroutine, we pass a single
derived data type around. Resulting code is much more readable all around.

A    metgrid/src/met_data_module.f90
M    metgrid/src/read_met_module.F90
M    metgrid/src/write_met_module.F90
M    metgrid/src/process_domain_module.F90
M    metgrid/src/Makefile
AM   util/src/met_data_module.f90
M    util/src/plotfmt.F90
M    util/src/avg_tsfc.F90
M    util/src/rd_intermediate.F90
M    util/src/mod_levs.F90
M    util/src/Makefile

git-svn-id: https://svn-wrf-wps.cgd.ucar.edu/trunk@345 86b71a92-4018-0410-97f8-d555beccfc3a