[svn-r9786] Purpose:

bug fix and document.

Description:
Unix and probably other systems too, has a small exit value range
such as 1 byte.  So, exit(256) may end up the same as exit(1).
Added caution message to the exit wrappers and changed test programs
to exit(1) when errors detected.

Platforms tested:
tested in copper.  verified here that exit(256) was treated just like
exit(0).

fortran/test/fortranlib_test.f90

@@ -336,9 +336,8 @@
 
      CALL h5close_f(error)
 
-     ! if errors detected, exit with non-zero code. This is not truly fortran
-     ! standard but likely supported by most fortran compilers.
-!     IF (total_error .ne. 0) CALL exit (total_error)
+     ! if errors detected, exit with non-zero code.
+     IF (total_error .ne. 0) CALL h5_exit_f (1)
 
     END PROGRAM fortranlibtest