Changelog: Copy editing

# Arti 1.1.6 — 30 June 2023

Arti 1.1.6 completes the core of the work needed for a client client

Arti 1.1.6 completes the core of the work needed for a client

to connect to onion services on the Tor network.  This is not yet

enabled by default: we do not yet recommend using this feature for

security-sensitive purposes, because of some

implementation. Currently it's used to store the keys needed for

client authentication, but in the future it will store the keys for

onion services themselves, and eventually relays.  In this release it

is still missing some import functionality for interoparability;

is still missing some import functionality for interoperability;

the interface is likely to change significantly.

Work on our RPC subsystem has also continued; we have achieved several

preqequisites needed for applications' SOCKS connections to

prerequisites needed for applications' SOCKS connections to

integrate correctly with the RPC subsystem.

And as usual, there are large number of smaller fixes and improvements

And as usual, there are a large number of smaller fixes and improvements

throughout the codebase.

### Major bugfixes

- We have removed an empty `relaycell::restrict` module from the

  `tor-cell` crate.  This module was added in error.  This change will

  break any code that (ineffectually) tried to import

  break any code that (pointlessly) tried to import

  it. ([589fefd581e962a7])

### Onion service development

- Onion service descriptors now have accessor functions to enable their

  actual use. ([!1220])

- We can transform the information about relays used in onion service

  desciptors, and in introduce1 cells, into the format needed to connect

  descriptors, and in introduce1 cells, into the format needed to connect

  to the relay described. ([!1221])

- Generate random rendezvous cookies to identify circuits at a client's

  rendezvous point. ([!1227])

- Remember our introduction point experiences, and try to use known-good

  ones before ones that have failed recently. ([!1247], [!1295])

- We now adjust the size of our pre-constructed circuit pool dynamically

  based on past demend for onion-service circuits (or lack

  based on past demand for onion-service circuits (or lack

  thereof). ([686d5cf2093322e4])

- Speed improvements to the algorithm we use to select pre-constructed

  circuits for onion services, and correctness fixes to those speed

  improvements. ([1691c353924f89cc], [#918], [!1296], [!1301])

- The StreamPrefs::connect_to_onion_services` method now can be used to

- The `StreamPrefs::connect_to_onion_services` method now can be used to

  enable or disable onion service connections, and TorClients can handle

  onion services correctly. ([!1257])

- Provide the extended SOCKS5 error codes as documented in [proposal

  RPC sessions. ([545984b095119ecc])

- `TorClient`s, and similar RPC-visible, can now be exposed with a

  secure global identifier so applications can refer to them outside of

  an RPC session This will allow applications to name a `TorClient` from

  an RPC session. This will allow applications to name a `TorClient` from

  e.g. within the parameters of a SOCKS connection. ([#863], [!1208])

- Enable `rpc::Object`s to be downcast to (some of) the `&dyn Trait`s

  that they implement. This is in tension with some of Rust's current