[Review] Request from 'schubi2' @ 'yast/yast-pkg-bindings/review_140924_flag_onsystem_by_user'

Please review the following changes:
  * 79f724d packaging
  * e3fecfa fixed PkgPropertiesAll
  * c2cb73d moved onSystemByUser to Package.cc
  * 6e7643d fixed name
  * 484da0f taking item pointer
  * 0468414 added onsystem_by_user flag

Ah, now I see. The first changelog entry should say that `on_system_by_user` is added to two `PkgProperties` and `ResolvableProperties`.

The second entry about `PkgPropertiesAll` seems dangerous without further explanation. Bugzilla does not explain that either. Please do explain it otherwise you risk breaking things in unexpected places.