Show progress when reconstructing blocks log with --hard-replay

[matthewdarwin]

When running "/opt/eosio/bin/nodeos --hard-replay --replay-blockchain" it would be nice to see some progress output to the log. Once per minute or so. On mainnet more than 10 minutes go by with no logs on a fast computer

Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.585 thread-0  http_plugin.cpp:422           plugin_initialize    ] configured http to listen on 0.0.0.0:8888
Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.585 thread-0  chain_plugin.cpp:335          plugin_initialize    ] initializing chain plugin
Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.585 thread-0  chain_plugin.cpp:494          plugin_initialize    ] Hard replay requested: deleting state database
Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.585 thread-0  block_log.cpp:368             repair_log           ] Recovering Block Log...
Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.588 thread-0  block_log.cpp:388             repair_log           ] Moved existing blocks directory to backup location: '/root/.local/share/eosio/nodeos/data/blocks-2018-12-27T15:53:16.585'
Dec 27 10:53:16 server1 nodeos[15900]: info  2018-12-27T15:53:16.588 thread-0  block_log.cpp:393             repair_log           ] Reconstructing '/root/.local/share/eosio/nodeos/data/blocks/blocks.log' from backed up block log
Dec 27 11:05:47 server1 nodeos[15900]: info  2018-12-27T16:05:47.225 thread-0  block_log.cpp:522             repair_log           ] Existing block log was undamaged. Recovered all irreversible blocks up to block number 34049752.
Dec 27 11:05:47 server1 nodeos[15900]: info  2018-12-27T16:05:47.245 thread-0  chain_plugin.cpp:504          plugin_initialize    ] Reversible blocks database was not corrupted. Copying from backup to blocks directory.
Dec 27 11:05:52 server1 nodeos[15900]: info  2018-12-27T16:05:52.627 thread-0  block_log.cpp:134             open                 ] Log is nonempty
Dec 27 11:05:52 server1 nodeos[15900]: info  2018-12-27T16:05:52.628 thread-0  block_log.cpp:178             open                 ] Index is empty
Dec 27 11:05:52 server1 nodeos[15900]: info  2018-12-27T16:05:52.628 thread-0  block_log.cpp:330             construct_index      ] Reconstructing Block Log Index...
...

[jgiszczak]

New logging added. There are two new progress messages, one for reconstruction of the index file and one for reconstruction of the block log file. The formats are, respectively:

Block log index reconstructed for block ####

and

Recovered block ####

where '####' is a block number. The log message appears every thousand blocks.