* introduce HeaderVersion (was u16) for type safety
cleanup pow ser/deser (version unused)
* fixup tests for HeaderVersion
* validate header version during header deserialization
* replace header_by_height index with reads into the header MMR
* rustfmt
* cleanup
* cleanup chain tests
* fix locate_headers to stop on our max header
* fix the deadlock in comact_blocks_db...
* cleanup and docs/comments
* Cuckatoo size shift upgrade schedule
* Move the schedule into graph_weight instead of messing with min edge bits
* Cleanup and fixes now that we have an agreed upon schedule
* PoW context is now properly picked depending on the chain type,
edge bits and block height. Height const for T4 hard fork leaving
a couple weeks to have miners in place. Removed now unused Cuckoo context.
* Simplified block siphash
* Fix servers crate compilation
* Tiny bit cleaner block siphash. Maybe.
* Cuckatoo min edge bits update for T4 and mainnet
* Fix header size tests, Cuckatoo31 default means one more bit per edge
* Remove redundant param from verify_size
* split horizon into two explicit values for cut through and txhashset request
* let node which has 2-7 days of history be able to handle forks larger than 2 days
* add test simulate_long_fork
* add pause/resume feature on p2p for tests
* refactor the state_sync
* ignore the test case simulate_long_fork for normal Travis-CI
* refactor function check_txhashset_needed to be shared with body_sync
* fix: state TxHashsetDone should allow header sync
* Replace logging backend to flexi-logger and add log rotation
* Changed flexi_logger to log4rs
* Disable logging level filtering in Root logger
* Support different logging levels for file and stdout
* Don't log messages from modules other than Grin-related
* Fix formatting
* Place backed up compressed log copies into log file directory
* Increase default log file size to 16 MiB
* Add comment to config file on log_max_size option
* header MMR in use within txhashset itself
works with fast sync
not yet in place for initial header sync
* add the (currently unused) sync_head mmr
* use sync MMR during fast sync
rebuild header MMR after we validate full txhashset after download
* support missing header MMR (rebuild as necessary) for legacy nodes
* rename to HashOnly
* cleanup backend.append()
* simplify vec_backend to match simpler append api
* First pass at secondary proof of work difficulty adjustments
* Core and chain test fixes
* Next difficulty calc now needs a height. Scaling calculation fixes. Setting scaling on mined block.
* Change factor to u32 instead of u64.
* Cleanup structs used by next_difficulty
* Fix header size calc with u32 scaling
* Go back to db for head and header_head
* Use batch consistently for db access
* Pass active txhashset and batch in the ctx
* Only update head in db if total work increases
* Only updated header_head if total work (on header chain) increases
* cuck placeholder
* rustfmt
* cuckatoo, early days
* rustfmt
* data structures are in place, siphash key creation is consistent with @tromp
* solver in place, (not yet working)
* cuckatoo test solver working with test nonce
* rustfmt
* update solver to remove adjacency list removals
* verifier functioning
* rustfmt
* Proper error handing in Cuckatoo module, couple of tests
* modify cuckoo/cuckatoo solvers and verifiers to function identically, in advance of trait refactoring
* rustfmt
* refactor PoW context into trait, default to using cuckoo context
* rustfmt
* create macros for integer casting/unwraps
* don't instantiate structs when just verifying, add test validation vector for cuckatoo 29
* rustfmt
* don't init cuckoo structs if just validating
* test fix
* ensure BH hashing for POW is only done within miner/validators
* 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
