starting to add fortran build to autotools

configure.ac

@@ -38,12 +38,18 @@ if test "x$enable_logging" = xyes; then
    AC_DEFINE([PIO_ENABLE_LOGGING], 1, [If true, turn on logging.])
 fi
 
+# Does the user want to enable Fortran library?
+AC_MSG_CHECKING([whether Fortran library should be build])
+AC_ARG_ENABLE([fortran],
+              [AS_HELP_STRING([--enable-fortran],
+                              [build the PIO Fortran library.])])
+test "x$enable_fortran" = xyes || enable_fortran=no
+AC_MSG_RESULT([$enable_fortran])
+AM_CONDITIONAL(BUILD_FORTRAN, [test "x$enable_fortran" = xyes])
+
 # NetCDF (at least classic) is required for PIO to build.
 AC_DEFINE([_NETCDF], [1], [netCDF classic library available])
 
-# Is parallel-netcdf library available?
-#AC_DEFINE([_PNETCDF], [1], [parallel-netcdf library available])
-
 # The PIO version, again.
 AC_DEFINE([PIO_VERSION_MAJOR], [2], [PIO major version])
 AC_DEFINE([PIO_VERSION_MINOR], [4], [PIO minor version])