BF: NETCDFPAR "Error" in build log when option not used

[davegill]

TYPE: bug fix

KEYWORDS: netcdfpar, Error

SOURCE: internal

DESCRIPTION OF CHANGES:
Problem:
With PR #1552 "Parallel netcdf-4 IO option" (SHA1 3cd4713), when then code was built without
the new parallel NetCDF4 compression, the build log had an Error.

> grep Error compile.log
Fatal Error: Cannot open module file ‘wrf_data_ncpar.mod’ for reading at (1): No such file or directory
make[2]: [diffwrf] Error 1 (ignored)
make[2]: [diffwrf] Error 1 (ignored)
wrf_io.f:117: Error: Can't open included file 'mpif.h'
make[2]: [wrf_io.o] Error 1 (ignored)
Fatal Error: Cannot open module file ‘wrf_data_ncpar.mod’ for reading at (1): No such file or directory
make[2]: [field_routines.o] Error 1 (ignored)
make[2]: [libwrfio_nfpar.a] Error 127 (ignored)
make[2]: [libwrfio_nfpar.a] Error 1 (ignored)

The problem was related to constructing the object files in the io_netcdfpar directory. When the
option is not selected at compile time, then we do not care about errors in the directory that will
never be used.

Solution:
If the NETCDFPAR option is not selected at compile time, then SKIP going into the io_netcdfpar
directory all together.

LIST OF MODIFIED FILES:
m Makefile
m arch/Config.pl
m arch/configure.defaults
m configure

TESTS CONDUCTED:

1. Without the NETCDFPAR parameter set, the build for the io_netcdfpar directory is bypassed:

          cd ../io_netcdfpar ; \
          echo SKIPPING make -i -r NETCDFPARPATH="/glade/u/apps/ch/opt/netcdf/4.7.3/gnu/9.1.0" \

          cd ../io_netcdfpar ; \
          echo SKIPPING make -i -r NETCDFPARPATH="/glade/u/apps/ch/opt/netcdf/4.7.3/gnu/9.1.0" \

2. When the NETCDFPAR env variable is set, the build includes the io_netcdfpar directory:
   cd ../io_netcdfpar ;
   make -i -r NETCDFPARPATH="/glade/u/apps/ch/opt/netcdf/4.8.0/gnu/9.1.0" \

      cd ../io_netcdfpar ; \
       make -i -r NETCDFPARPATH="/glade/u/apps/ch/opt/netcdf/4.8.0/gnu/9.1.0" \
   

3. Jenkins tests are all PASS.

[davegill]

@weiwangncar @kkeene44 @smileMchen
Folks,
This PR fixes the non-fatal error that users in their build logs. It was introduced by the parallel netcdf4 PR #1552. What failed was a build of a file that would never be used. Could you review please - we need 2.

[davegill]

@dwongepa
David,
Does this branch fix the CMAQ coupling build?

[davegill]

@dwongepa
David,
cherry pick these commits onto the CMAQ branch