ciri: Support Milestones of higher security level and different hashing function

[alon-e]

In cIRI you track milestones of security level 1 w/ Curl-P-27.
IRI supports also different hashing functions and higher security level:

• Enable validation of milestones with additional hash modes and security levels  iri#1041
• refactor milestone signature parameters to be configurable iri#1322

This is needed for transitioning to the new Milestone structure supported by Compass.

entangled/consensus/milestone_tracker/milestone_tracker.c

Lines 43 to 63 in 43d4bdf

	Curl curl;
	*valid = false;
	flex_trits_to_trits(signature_trits, NUM_TRITS_SIGNATURE,
	transaction_signature(tx1), NUM_TRITS_SIGNATURE,
	NUM_TRITS_SIGNATURE);
	flex_trits_to_trits(siblings_trits, NUM_TRITS_SIGNATURE,
	transaction_signature(tx2), NUM_TRITS_SIGNATURE,
	NUM_TRITS_SIGNATURE);
	curl.type = CURL_P_27;
	init_curl(&curl);
	normalize_flex_hash_to_trits(transaction_trunk(tx1), normalized_trunk_trits);
	iss_curl_sig_digest(sig_digest, normalized_trunk_trits, signature_trits,
	NUM_TRITS_SIGNATURE, &curl);
	curl_reset(&curl);
	iss_curl_address(sig_digest, root, HASH_LENGTH_TRIT, &curl);
	merkle_root(root, siblings_trits, mt->conf->num_keys_in_milestone,
	candidate->index, &curl);
	flex_trits_from_trits(coo, HASH_LENGTH_TRIT, root, HASH_LENGTH_TRIT,
	HASH_LENGTH_TRIT);

[thibault-martinez]

Implemented by #996 and #999