Add standalone netperf code directly within site_wifitest

Create a version of netperf test directly within site_wifitest that:

  - Only runs if netperf is pre-installed on both client and server
  - Knows about opening a hole for the netperf control socket in the netbook firewall
  - Can start up the netserv on one end, and netperf on the other
  - Parses the output of netperf itself, and will make separate perf
    numbers for each netperf run within the test suite
  - A few fixes to the "ping" code so that each iteration of ping stats are displayed

BUG=none
TEST=Run MatFunc 034* -- running full MatFunc while I sleep

Review URL: http://codereview.chromium.org/3275009
5 files changed