BC_API -> BCB_API
generate fake blocks to test blockchain.
improve fakechain run.sh script.
improve benchmark tool to generate random rows and be more efficient.
renamed chain_keeper to simple_chain and renamed methods more clearer.
split fetch_history into its own unit.
rename hdb to hsdb (history scan database)
actually randomise values for shard bench
hsdb settings
avoid recalculating settings.scan_bitsize(), use struct method instead.
hsdb_settings
history scan database wrapper for hsdb_shards