* Upgrade Rust to 1.52.0
update nightly_version to newly pushed docker image
fix clippy lint errors
1.52 comes with grcov 0.8.0, include this version to script
* upgrade to Rust 1.52.1
* disabling Serum from downstream projects until it is upgraded to Rust 1.52.1
* purge_old_snapshot_archives is changed to take an extra argument 'maximum_snapshots_to_retain' to control the max number of latest snapshot archives to retain. Note the oldest snapshot is always retained as before and is not subjected to this new options.
* The validator and ledger-tool executables are modified with a CLI argument --maximum-snapshots-to-retain. And the options are propagated down the call chains. Their corresponding shell scripts were changed accordingly.
* SnapshotConfig is modified to have an extra field for the maximum_snapshots_to_retain
* Unit tests are developed to cover purge_old_snapshot_archives
* Deprecate commitment variants
* Add new CommitmentConfig builders
* Add helpers to avoid allowing deprecated variants
* Remove deprecated transaction-status code
* Include new commitment variants in runtime commitment; allow deprecated as long as old variants persist
* Remove deprecated banks code
* Remove deprecated variants in core; allow deprecated in rpc/rpc-subscriptions for now
* Heavier hand with rpc/rpc-subscription commitment
* Remove deprecated variants from local-cluster
* Remove deprecated variants from various tools
* Remove deprecated variants from validator
* Update docs
* Remove deprecated client code
* Add new variants to cli; remove deprecated variants as possible
* Don't send new commitment variants to old clusters
* Retain deprecated method in test_validator_saves_tower
* Fix clippy matches! suggestion for BPF solana-sdk legacy compile test
* Refactor node version check to handle commitment variants and transaction encoding
* Hide deprecated variants from cli help
* Add cli App comments
* Discard pre hard fork persisted tower if hard-forking
* Relax config.require_tower
* Add cluster test
* nits
* Remove unnecessary check
Co-authored-by: Ryo Onodera <ryoqun@gmail.com>
Co-authored-by: Carl Lin <carl@solana.com>
* Fix tower/blockstore unsync due to external causes
* Add and clean up long comments
* Clean up test
* Comment about warped_slot_history
* Run test_future_tower with master-only/master-slave
* Update comments about false leader condition
* Follow up to persistent tower
* Ignore for now...
* Hard-code validator identities for easy reasoning
* Add a test for opt. conf violation without tower
* Fix compile with rust < 1.47
* Remove unused method
* More move of assert tweak to the asser pr
* Add comments
* Clean up
* Clean the test addressing various review comments
* Clean up a bit