SystemC Blockdiagram

SystemC Blockdiagram (without wiring)
Wiring will come separately, because I still have my hard time figuring out how to get the right informations for displaying ports and signals. 

 * Contains only svg stuff that is needed for displaying the SystemC Blockdiagram.
 * Contains the STL implementation I pulled from Kevin

I think it is for the better to send this pull request now, because you can test while the others are still trying to fix their STL implementation.