Today the `elasticsearch-shard remove-corrupted-data` tool will only truncate a
translog it determines to be corrupt. However there may be other cases in which
it is desirable to truncate the translog, for instance if an operation in the
translog cannot be replayed for some reason other than corruption. This commit
adds a `--truncate-clean-translog` option to skip the corruption check on the
translog and blindly truncate it.
James Rodewig
David Turner
Vladimir Dolzhenko