- Arbitrary remove objects and delete workflow history is bad. This code
  was never used anyway.
 - Clean up code which is not used anywhere anymore, legacy from long ago
  implementation.

 - Create System Preference if do not exist
 - Handle BusinessTemplateUnknownError when portal_templates is unable to handle depedencies.

Thanks to this Computer Partitions can be in same category as Computers they
are contained in.

It will be used to represent various Computer models.

It will be used to create group of Computer.

Acknowledgement can not be displayed without more informations.