Squashed commit of the following:

commit 9bbe65d1e607e1501c1224264b1b14f2542df504
Author: Ivan Mihnenok <imi@eiendomsinfo>
Date:   Sat Oct 25 22:25:13 2014 +0300

    - removed hasMetadata field from SongEntity and Song structure, it is not used
    - restructured controllers

commit 5bf254622ad11ea9ac2cb57db5c24a6be04f4009
Author: Ivan Mihnenok <imi@eiendomsinfo>
Date:   Sat Oct 25 21:30:34 2014 +0300

    Fix. Before was passed songName instead of sonId. therefore song wasn't found and was thrown exception when was needed to update metadata
    - small improvements for test

commit e11c30a8849a79327622b2fe701f2a99e183c3b1
Author: Ivan Mihnenok <imi@eiendomsinfo>
Date:   Wed Oct 22 23:23:14 2014 +0300

    Fixes, related to serialization json to javaobject.
    added annotation which skip unknown fields in json. Before was thrown exception