[#77193030] package-model listing package-items related to the inventory_pool as responsible

Squashed commit of the following:

commit ac7f705612a631357424e6a12f53a65bfc42ba23
Merge: f4229f8 3c48c47
Author: Franco Sellitto <franco.sellitto@zhdk.ch>
Date:   Fri Aug 22 15:40:25 2014 +0200

    Merge branch 'master' into fs_packages

commit f4229f8ef714d1791795753f57727f7a70133507
Author: Franco Sellitto <franco.sellitto@zhdk.ch>
Date:   Fri Aug 22 14:25:12 2014 +0200

    fixing scope for package items list