* introduce rewindable_kernel_view
cleanup header in extension
* cleanup and docs/comments
* txhashset does not need to be mutable here
* pull validate_kernel_history out into fn
* block_sums and full kernel sum verification
* rustfmt
* add docs/comments
* docs
* rustfmt
* comment on fact total_kernel_sum is redundant now
* make sure we setup block_sums correctly on a fork
* rustfmt
* replace those asserts with errors
* rustfmt
* Move Proof and Difficulty types to pow module. Difficulty scaling calculation.
* Diffculty scaling and size shift for 2nd PoW
* Backport e7eb26ee
* Test compilation fixes
* Scaling only need to go one way, as @tromp pointed out
* document what we do during pipe::apply_block()
* rustfmt
* wip
* rustfmt
* wip
* additional check_known_store and check_known_mmr checks in process_block
* rustfmt
* cleanup coinbase maturity check in process_block
* consolidate the "check in store" logic
add TODOs around the 50 block OldBlock logic
* rustfmt
* cleanup
* fix: if block in orphans queue has a forked parent, cause infinite loop in check_orphans()
* process all orphans at a given height before go to next height
* refactor txhashset to only take a single header
no need to pass in current head_header each time
* rustfmt
* fix bug introduced in rewind with LMDB
* rustfmt
* add some comments
* Check txhashset content before zip/unzip
* Add header in txhashset verification
* Add copy function and test
* Add file util
* Now check and remove unexpected files instead of just crashing
* improve: time crate flagged as deprecated, switch to actively maintained chrono crate
* improve: complete the switching from deprecated time crate to chrono crate, for all the tests part
* improve: complete switching to chrono crate, for the left tests in 'chain' and 'wallet'
* Refactor hash cache handling to add properly. Only add to cache if the block is definitevely accepted or rejected.
* Dedup of header processing now looks like premature optimization. Very fast anyway. Removing the header hash cache.
* Remove now unnecessary txhashset write lock
* Ring buffer of hashes the chain has already processed
* Specifically report too old blocks as peer should be banned
* Move sync check for block relay, clean TODO
* No use processing transactions when syncing
* Ignore blocks older than horizon in pruning nodes
* fix misbehaving simulnet fastsync test
cleanup redundant cutoff vs bitmap params is rewind and check_compact
* make sure we do not verify full kernel history on a writeable txhashset extension
rework simulnet simulate_fast_sync test to be more robust
* fixup store tests
* sleep for a bit longer to give nodes time to update
their sync_state correctly
* tweak timing of simulate_block_propagation
* Handle SIGINT and SIGTERM (#1180)
* Handle SIGINT and SIGTERM
* pin croaring to version 0.3.2 until we get the clang conflict sorted out (#1183)
* document proposals for - (#1190)
* conditional timelocked outputs, and
* conditional relative timelocked outputs
* problem with validation on rewind
* update difficulty scenarios to display much more data
* correct average sum output
* update pre-genesis block padding to just use previous block's data
