Refactored parsing of superclass into own method

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Loading a class should register it as a global

I think this is sensible, because it is also checking whether it is registered already

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added ClassStructure test to SomTests

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added #halt primitive

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Use simple class name instead of fully-qualifed one

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Make sure that superclass of Object is nil

- updated to latest core-lib

Signed-off-by: Stefan Marr <git@stefan-marr.de>