Added formulas for ntopng and ndpi

Dear all, please find enclosed the formulas for two open source tools ntop develops:
- nDPI: SDK for deep-packet inspection
- ntopng: web-based traffic monitoring application.

Thanks Luca Deri
I think that the most I can do is to check if the package starts and all dependencies are satisfied. As ntopng requires root privileges to start I cannot perform a live capture. Packaging a static pcap file might also be an option, but due to the nature of ntopng e we need to add considerable efforts in creating a testing infrastructure. I think that checking the package startup can be a good option for this first release.