Merge bitcoin#9531: Release notes for estimation changes

34ede12 Document fee estimation changes (Alex Morcos)
b348287 Clarify that prioritisetransaction remains supported (Alex Morcos)

doc/release-notes.md

@@ -48,6 +48,17 @@ Low-level RPC changes
   an optional third arg, which was always ignored. Make sure to never pass more
   than two arguments.
 
+Fee Estimation Changes
+----------------------
+
+- Since 0.13.2 fee estimation for a confirmation target of 1 block has been
+  disabled. This is only a minor behavior change as there was often insufficient
+  data for this target anyway. `estimatefee 1` will now always return -1 and
+  `estimatesmartfee 1` will start searching at a target of 2.
+
+- The default target for fee estimation is changed to 6 blocks in both the GUI
+  (previously 25) and for RPC calls (previously 2).
+
 Removal of Priority Estimation
 ------------------------------
 
@@ -58,9 +69,11 @@ Removal of Priority Estimation
   converted to the new format which is not readable by prior versions of the
   software.
 
-- The concept of "priority" transactions is planned to be removed in the next
-  major version. To prepare for this, the default for the rate limit of priority
-  transactions (`-limitfreerelay`) has been set to `0` kB/minute.
+- The concept of "priority" (coin age) transactions is planned to be removed in
+  the next major version. To prepare for this, the default for the rate limit of
+  priority transactions (`-limitfreerelay`) has been set to `0` kB/minute. This
+  is not to be confused with the `prioritisetransaction` RPC which will remain
+  supported for adding fee deltas to transactions.
 
 P2P connection management
 --------------------------