* expose leaf pos iterator
use it for various things in txhashset when iterating over outputs
* fix
* cleanup
* rebuild output_pos index (and clear it out first) when compacting the chain
* fixup tests
* refactor to match on (output, proof) tuple
* add comments to compact() to explain what is going on.
* get rid of some boxing around the leaf_set iterator
* cleanup
* 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
* 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
* implement prune_list as a bitmap
and simplify
* cleanup prune_list, use maximum()
* handle migration of prune_list to new bitmap prun file
* legacy filename consts
* cleanup and docs
* Add kernel commitments sum and kernel and output MMR sizes to block header
* Sum a block without including previous sums, cleanup. Blocks are now summed and validated based on their own totals and not the totals since genesis. This allows to get rid of BlockSum and simplified the setting of a new block's roots, kernel sum and MMR sizes. Fixes#116
* Additional kernel MMR validation to check all prior header roots successively
* Wallet tests fix
* only store leaves in rm_log
* cleanup
* commit
* add failing test to cover case where we compact
an already compacted data file
* fix the logic for pruning the data file
* rm_log only contains leaves
prunelist only contains non-leaf subtree roots
* cleanup
* commit
* bitmap impl running in parallel
* rustfmt
* this is better - rewind unremoves outpu pos spent by rewound inputs
* commit
* commit
* pass bitmap around when rewinding
* store and retrieve input bitmap per block from the db
* Replace the RemoveLog with the UTXO set.
* utxo set starting to pass tests
* stuff works...
* split store types out
added some tests to compare the performance of the rm_log and the proposed utxo_set
* pull prune_list out into standalone file
* cleanup, get rid of unused height param
* cleanup and add doc comments
* add support for migrating rm_log to utxo_set
* take snapshot of utxo file during fast sync
implement migration of rm_log -> utxo_set
* rename rewound_copy to snapshot
* fixup pmmr tests to reflect cutoff_pos
* cleanup unused import
* check_compact needs to rewind the utxo_set as appropriate
* fix pool tests
* fixup core tests
* cache block_input_bitmaps via LruCache in store
* cache block header on initial write to db
* rename utxo_set -> leaf_set
and remove references to "spent" in grin_store
* better document the rewind behavior
