Modularized code in user and person model

Squashed commit of the following:

commit 08cadabd46c0fc07327633e09adb9a81c0d5c980
Author: Thomas Schank <DrTom@schank.ch>
Date:   Wed Mar 19 08:56:56 2014 +0100

    Fix: moved module to proper place

commit 0c45cf7446b86e429c05f200dcad1aca5cab594b
Author: Thomas Schank <DrTom@schank.ch>
Date:   Wed Mar 19 08:34:20 2014 +0100

    Modularized person model

commit 250a7d3fe64399d7738060552ae62f848f2d11c9
Author: Thomas Schank <DrTom@schank.ch>
Date:   Wed Mar 19 08:22:21 2014 +0100

    Modularized user's search_code into module

commit 7aec8ec9b989f482251afff7667ea54a283cf22c
Author: Thomas Schank <DrTom@schank.ch>
Date:   Wed Mar 19 08:01:51 2014 +0100

    Modularize user's dropbox