Need to process EAP AVP after the non-EAP Phase 2 method. In addition,
EAP-TTLS/MSCHAPv2 needs special code for handling the starting of TNC after
extra roundtrip of MSCHAPv2 success message.
Number of TLVs were processed in groups and these cases were now separated
into more flexible processing of one TLV at the time. wpabuf_concat()
function was added to make it easier to concatenate TLVs. EAP Sequences are
now supported in both server and peer code, but the server side is not
enabled by default.