eap.h support for tunneled callbacks

eap.h		support for tunneled callbacks
rlm_eap.c	update request->proxy in authenticate
		call tunneled callbacks in postproxy

types/rlm_eap_ttls/eap_ttls.h
types/rlm_eap_tls/eap_tls.h
	move prototype for eapttls_process

types/rlm_eap_peap/eap_peap.h
	include rlm_eap.h

types/rlm_eap_peap/rlm_eap_peap.c
types/rlm_eap_ttls/rlm_eap_ttls.c
	handle "updated" return code from tunnel handler

types/rlm_eap_peap/peap.c
types/rlm_eap_ttls/ttls.c
	hoist reply processing into it's own routine.
	handle proxy replies