hdf5_ep

[svn-r9111] Purpose:
Update.

Description:
Make some minor change so that h5jam.c is compatible with Windows.

Solution:
1. unistd.h is not available in windows system.  Add a macro for this header file as:
   #ifdef H5_HAVE_UNISTD_H
   #include <unistd.h>
   #endif
2. Change open, read, write, lseek functions to HDopen, HDread, HDwrite, and HDlseek,
   as these HD functions are more comtatible with Windows system.
3. add #include H5private.h
4. remove #include <stdlib.h>

Platforms tested:
Windows 2000
Windows XP
eirene
(Note:  I talked with Bob and Kent about these changes before check-in)

Misc. update: