Import WiFi performance measurement scripts.

These scripts are an evaluation suite for WiFi performance:
*  sample - gather performance measurements (using iperf and passive
     tcpdump) from a WiFi station, and write them to the filesystem.
*  report - Collate multiple performance measurements into a table that
     displays rate-over-range.

Tested on available Mac (early 2013 Macbook Pro) and Linux (TV Box)

Change-Id: Iaf9272038c1fc12129d30107c0c65fcddcb13b1c
22 files changed