vchoi_fork

[svn-r12949] Description:
    Finish implementation of H5Literate() [still needs real tests]

    Clean up datatype macro warnings a bit more.

    Unify iterator callback macros and put up in public header file, with the
iterator directions.

Tested on:
    Mac OS X/32 10.4.8 (amazon)
    FreeBSD/32 4.11 (sleipnir)
    Linux/32 2.4 (heping)
    Linux/64 2.4 (mir)
    AIX/32 5.? (copper)