802.1x EAP-TLS Authentication for wifi tests

Added the 802.1x authentication method to the list of tests.  This
involved upgrading all the testbed machines to use a hostapd that had
the internal radius server enabled, reconfiguring site_wlan_connect to
be able to pass the right parameters to flimflamd in order to do a
file-based certificate authentication, and adding both client and server
routines to site_wifi.

The certificate information is hard-coded in site_eap_tls.py.  The
actual key content is less interesting than the fact that this data is
usable.

Note that this test does not use the TPA to perform authentication since
this requires entd to be running, and a user logged in on console, etc.,
etc., which is difficult to accomplish over ssh.

TEST=Run test suite
BUG=none

Review URL: http://codereview.chromium.org/3139013
5 files changed