vchoi_fork

[svn-r12992] Description:
    Add fields for tracking attributes on objects to object header prefix,
when using the latest version of the format.

    Reduce size used to store type of header message from 2 bytes to 1. (If we
have >256 message types, we probably have a different problem... :-)

    Also, add "birth" time for object (i.e. creation time) [named to align
with similar fields in file systems]

    Correct bug in H5Gget_objinfo() - retrieve the ctime field from object info,
instead of the mtime field.

Tested on:
    Linux/32 2.6 (chicago)
    Linux/64 2.6 (chicago2)