Bitcoin ABC version 0.18.3 is now available from:

  <https://download.bitcoinabc.org/0.18.3/>

This release includes the following features and fixes:
 - Remove support for Qt4
 - Upgrade reproducible build to use Qt 5.9.6
 - Improve SHA256 performance using SSE4.1, AVX2 and/or SHA if available.
 - Add a mode argument to the `getmemoryinfo` RPC call to query `malloc_info` from the system if available.
 - Updated univalue library to version 1.0.4
 - Disable safe mode by default
 - Added autocomplete to 'help' in RPC console
 - Deprecated estimatefee RPC command
 - Improved help message for backup wallet RPC
 - Various bug fixes that improve node stability and performance
 - Backport getblock RPC's new verbosity mode from bitcoin core for retrieving all transactions of a given block in full.
 - Added 'parked' state to getchaintips RPC
 - RPC `listreceivedbyaddress` now accepts an address filter
 - Backport combinerawtransaction RPC from bitcoin core to combine multiple partially signed transactions into one transaction.
Bitcoin ABC version 0.18.3 is now available from:

  <https://download.bitcoinabc.org/0.18.3/>

This release includes the following features and fixes:
 - Remove support for Qt4
 - Upgrade reproducible build to use Qt 5.9.6
 - Improve SHA256 performance using SSE4.1, AVX2 and/or SHA if available.
 - Add a mode argument to the `getmemoryinfo` RPC call to query `malloc_info` from the system if available.
 - Updated univalue library to version 1.0.4
 - Disable safe mode by default
 - Added autocomplete to 'help' in RPC console
 - Deprecated estimatefee RPC command
 - Improved help message for backup wallet RPC
 - Various bug fixes that improve node stability and performance
 - Backport getblock RPC's new verbosity mode from bitcoin core for retrieving all transactions of a given block in full.
 - Added parkblock/unparkblock RPC commands and 'parked' state to getchaintips RPC
 - RPC `listreceivedbyaddress` now accepts an address filter
 - Backport combinerawtransaction RPC from bitcoin core to combine multiple partially signed transactions into one transaction.

Fix up release note on parked chain RPC
Fix up release note on parked chain RPC

Summary: Missed adding a note on the new RPC commands

Test Plan: Read it

Reviewers: deadalnix, schancel, Fabien, #bitcoin_abc

Reviewed By: deadalnix, schancel, Fabien, #bitcoin_abc

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D2020
