This is used to get arbitrary information out of the EAP method. Needed
for EAP-WSC to signal credential information obtained from the peer.
Other uses include signaling why EAP-WSC failed (e.g. invalid PIN, etc)
and processing of M2D discovery messages. The information in M2Ds might
be useful to external clients.
Only EAP as the inner authentication option is supported. According to
wikipedia this is the most popular EAP-TTLS use case, with MD5 as the
inner EAP's method.
Add the EAP-TLS authentication method. Currently, all the credentials
data is read from the provisioning file even though things like the
private key passphrase should possibly be obtained from the dbus agent.
