Disable netCDF Fortran 2003 interface by default.

Most applications use the netCDF F90 interface.  We will by default
select the --disable-f03 flag option to configure when building the
library netcdf-fortran.4.4.1.

The user can request the Fortran 2003 interface by compiling with
the F2003=yes option.

Signed-off-by: Bob Yantosca <yantosca@seas.harvard.edu>