Implement subject_filter functionality for subject_listing view

@maethu @buchi 

Updated the subject_listing view.

You can add a var in manage_propertiesForm or you can add a request variable:

name: subject_listing
value: string

The view will display just objects related to this subject:

Defaultview:

![bildschirmfoto 2013-11-08 um 14 39 32](https://f.cloud.github.com/assets/557005/1500603/3e234ed4-487b-11e3-8c05-5b70bf2bd0d9.png)

With subject_filter:

![bildschirmfoto 2013-11-08 um 14 39 17](https://f.cloud.github.com/assets/557005/1500607/525e36f2-487b-11e3-8572-e3f2278382bd.png)