object debugging infrastructure V2

This is version 2 of the object debugging infrastructure. Changes
versus V1:

- review comments processed:
  - multiplexing interfaces replaced
  - object type is determined by a caller provided pointer to 
    a debug structure which replaces the object type identifier
    -> No changes to the core code for new users
  - new debug state "destroyed" (kobject wishlist)
  - various cleanups

- complete detachment of the tracker object from the real object
  (no change to the real objects data structure necessary anymore)

- improved robustness (object memory management, oom cleanup)

- full set of self tests

- debugfs statistics 

- docbook documentation

Thanks,

	tglx
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