[Feature] rspamd_stats: support log directory reading
[Feature] rspamd_stats: support log directory reading

rspamd_stats will read (and decompress) multiple log files in the specified directory.

AlexeySa/rspamd,minaevmike/rspamd,AlexeySa/rspamd,minaevmike/rspamd,minaevmike/rspamd,AlexeySa/rspamd,minaevmike/rspamd,AlexeySa/rspamd,minaevmike/rspamd,minaevmike/rspamd,minaevmike/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,minaevmike/rspamd,AlexeySa/rspamd,minaevmike/rspamd