vchoi_fork

[svn-r3238] Purpose:
    Bug fix
Description:
    The zlib.h header check was skipped if it thought it had
    found -lz already.  That resulted in H5_HAVE_ZLIB_H not defined
    which caused compression feature not compiled even though everything
    else said it was in.
    The --with-hdf4 was default to yes but configure had no clue where to
    find them.  A plain waste of time and affected ZLIB's searching later.
Solution:
    Basically restored what it was before--checking the optional switch
    of with-hdf4 first, then with-zlib.  (with-hdf4 now defaults to no.)
    Added a big chunk of comments explaining why these two options must
    be checked in this order.
    Changes applied to configure.in.  Then ran autoconf to generate
    configure.
Platforms tested:
    eirene (default and with-hdf4), modi4-64-parallel (with-hdf4),
    arabica (with-hdf4) and, gondoline.  That is right, even tested
    it out with gondoline (with-hdf4 too.)  All except modi4 configured,
    compiled and tested correctly.  Modi4 died in the compiling of
    src/H5Zdeflate.c but that was not due to the configure changes.