Release notes:

Stability improvements

• Overlay flow control not enabled by default for now as it’s a major update to how peers communicate with each other for better performance regardless of peer types.
• Clear state if stellar-core aborts while applying buckets this fixes an edge case that could lead the ledger in a bad state if the node was stopped at the wrong time.
• Log as much uncaught-exception info as we can, fixes [#3155].
• Actually enforce SHA256 contract
• Rename maxTxSize to maxTxSetSize.
• Cleanup logic for checking protocol versions.
• Rename isString32Valid to isStringValid
• Log exception as INFO (instead ERROR) for older protocol version
• Only git clean ignored files in Dockerfile.testing
• Simulation updates and fixes
• Add TrustFlagsOpFrameBase to Visual Studio project.
• Return early in updateEntryIfRecorded if entry is not an offer
• Update catch2 to 2.13.8
• Unify trustline op
• Bump spdlog1.9.2

New features

• Make validators from the same home domain preferred peers. This implements a best practice that validators within the same organization should utilize internal bandwidth when possible.
• Adding an option to halt on txINTERNAL_ERROR. - this allows to configure certain nodes to never externalize ledgers that may have run into unexpected problems.

Breaking changes

• Remove MINIMUM_IDLE_PERCENT and TMP_DIR_PATH from core config.