ssb: Invite support progress. Now the pub accepts the invite, tracks its use, and follows. The client still needs to react.

src/ssb.db.h

@@ -516,6 +516,14 @@ const char* tf_ssb_db_get_profile_name(sqlite3* db, const char* id);
 */
 bool tf_ssb_db_generate_invite(sqlite3* db, const char* id, const char* host, int port, int use_count, int expires_seconds, char* out_invite, size_t size);
 
+/**
+** Consume and validate an invite.
+** @param db The database.
+** @param id The invite public key.
+** @return true If the invite was valid and successfully consumed.
+*/
+bool tf_ssb_db_use_invite(sqlite3* db, const char* id);
+
 /**
 ** An SQLite authorizer callback.  See https://www.sqlite.org/c3ref/set_authorizer.html for use.
 ** @param user_data User data registered with the authorizer.