XStream class aliases

* remove packagename from xstream generated code.xml with xstream.alias!
* xstream alias for LookData -> look and SoundInfo -> sound
* fix type in tag <url>
* remove unused code.xml files for testing our (removed) serializer/parser

successful testrun: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test/514/