Merge #15314: [Doc] update release notes for changes up to cb35f1d

5d35d43 Update release notes through to cb35f1d (David A. Harding)
9ad5ca1 Release notes: integrate detached & rm backports (David A. Harding)

Pull request description:

  Monthly release notes update.  ~~In addition to a few new notes, this removes from the master branch two notes about things that have been backported to the 0.17 branch (though not released yet): `unloadwallet` RPC now being blocking (0.17 has a detached release note for that) and the PSBT doc (0.17 does not have a release note for that; I'll open a PR).~~

Tree-SHA512: 569b651f2ec4d6d22c2410897f6980a0db2d9aad479730537f0c77cc8d905599a4e6d1db716720fec55a4ee77dd0bd5de9d02a0f636b63cd68ece61d24547af0

Author: MarcoFalke

doc/release-notes-14941.md

@@ -116,7 +116,8 @@ Configuration option changes
   defaults to being off, so that changes in policy and disconnect/ban behavior
   will not cause a node that is whitelisting another to be dropped by peers.
   Users can still explicitly enable this behavior with the command line option
-  (and may want to consider letting the Bitcoin Core project know about their
+  (and may want to consider [contacting](https://bitcoincore.org/en/contact/)
+  the Bitcoin Core project to let us know about their
   use-case, as this feature could be deprecated in the future).
 
 Documentation
@@ -130,6 +131,10 @@ Documentation
   to the [REST interface documentation](https://github.com/bitcoin/bitcoin/blob/master/doc/REST-interface.md)
   indicating that the same rules apply.
 
+- Further information is added to the [JSON-RPC
+  documentation](https://github.com/bitcoin/bitcoin/blob/master/doc/JSON-RPC-interface.md)
+  about how to secure this interface.
+
 - A new [document](https://github.com/bitcoin/bitcoin/blob/master/doc/bitcoin-conf.md)
   about the `bitcoin.conf` file describes how to use it to configure
   Bitcoin Core.
@@ -190,14 +195,18 @@ Deprecated or removed RPCs
 New RPCs
 --------
 
-- A new `getnodeaddresses` RPC returns peer addresses known to this
+- The `getnodeaddresses` RPC returns peer addresses known to this
   node. It may be used to find nodes to connect to without using a DNS
   seeder.
 
-- A new `listwalletdir` RPC returns a list of wallets in the wallet
+- The `listwalletdir` RPC returns a list of wallets in the wallet
   directory (either the default wallet directory or the directory
   configured by the `-walletdir` parameter).
 
+- The `getrpcinfo` returns runtime details of the RPC server. At the
+  moment, it returns an array of the currently active commands and how
+  long they've been running.
+
 Updated RPCs
 ------------
 
@@ -260,6 +269,16 @@ in the Low-level Changes section below.
   2. If no blockhash is provided, check the mempool. 3. If no blockhash
   is provided but txindex is enabled, also check txindex.
 
+- The `unloadwallet` RPC is now synchronous, meaning it will not return
+  until the wallet is fully unloaded.
+
+REST changes
+------------
+
+- A new `/rest/blockhashbyheight/` endpoint is added for fetching the
+  hash of the block in the current best blockchain based on its height
+  (how many blocks it is after the Genesis Block).
+
 Graphical User Interface (GUI)
 ------------------------------
 
@@ -282,6 +301,16 @@ Graphical User Interface (GUI)
   CFLAGS="-mmacosx-version-min=10.11" for setting the deployment
   sdk version)
 
+Tools
+----
+
+- A new `bitcoin-wallet` tool is now distributed alongside Bitcoin
+  Core's other executables.  Without needing to use any RPCs, this tool
+  can currently create a new wallet file or display some basic
+  information about an existing wallet, such as whether the wallet is
+  encrypted, whether it uses an HD seed, how many transactions it
+  contains, and how many address book entries it has.
+
 Low-level changes
 =================
 
@@ -306,6 +335,32 @@ Configuration
   deterministic wallets. This release makes specifying `-usehd` an
   invalid configuration option.
 
+Network
+-------
+
+- This release allows peers that your node automatically disconnected
+  for misbehavior (e.g. sending invalid data) to reconnect to your node
+  if you have unused incoming connection slots.  If your slots fill up,
+  a misbehaving node will be disconnected to make room for nodes without
+  a history of problems (unless the misbehaving node helps your node in
+  some other way, such as by connecting to a part of the Internet from
+  which you don't have many other peers).  Previously, Bitcoin Core
+  banned the IP addresses of misbehaving peers for a period of time
+  (default of 1 day); this was easily circumvented by attackers with
+  multiple IP addresses.  If you manually ban a peer, such as by using
+  the `setban` RPC, all connections from that peer will still be
+  rejected.
+
+Security
+--------
+
+- This release changes the Random Number Generator (RNG) used from
+  OpenSSL to Bitcoin Core's own implementation, although entropy
+  gathered by Bitcoin Core is fed out to OpenSSL and then read back in
+  when the program needs strong randomness.  This moves Bitcoin Core a
+  little closer to no longer needing to depend on OpenSSL, a dependency
+  that has caused security issues in the past.
+
 Changes for particular platforms
 --------------------------------