Major features include beginning of implementation of next-generation hidden services: Relays can now handle v3 ESTABLISH_INTRO cells as specified by prop224 aka “Next Generation Hidden Services”. Service and clients don’t use this functionality yet. Closes ticket 19043. Based on initial code by Alec Heifetz. and Relays now support the HSDir version 3 protocol, so that they can can store and serve v3 descriptors. This is part of the next- generation onion service work detailled in proposal 224. Closes ticket 17238.
This is what we use the release tag for. ;)