Port of Stubbles IoC to XP

Hi,

I just added the port of the Stubbles IoC mechanism to XP. It comes with full unit test coverage, but no further integration into the framework. It may have issues with the XP coding standard, please feel free to point those out.

I do not intend that this pull request gets merged soon (however: feel free if you want to ;), it should be used as a platform to discussion on what should be improved or even how it might be integrated into the framework itself beside being available as code.

Regards,
Frank