Added BlockPrimitives and DoublePrimitives

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

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

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added missing accessors for global classes

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added work-around for use of exit()

- the same as for SOM and TruffleSOM

Signed-off-by: Stefan Marr <git@stefan-marr.de>
This is PySOM!

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