Differentiate sniffer application platforms and platforms which generate PCAPs via FIFOs

[sdawans]

The existing documentation lacks explanations on how to hook-up some hardware sniffers to Foren6 via FIFOs.

The Contiki sniffer application we provide doesn't cover all platforms. For Econotag, for example, we use libmc1322x's rftestrx2pcap.py to write to a FIFO, which is read by Foren6.

Changes needed:

• Categorize the instructions by platform (more user-friendly)
• Add specific instructions for Econotag (rftestex2pcap --> FIFO --> Foren6)
• Add specific instructions for rzusbstick (dumpcap --> FIFO --> Foren6)

[sdawans]

Done for Econotag.

Platforms left:

• rzusbstick
• zena
• COOJA