enhance ngxtop ability

[Oh-Little-Papaya]

1 add ngxtop to handler multi log_path 2 add ngxtop ability to handler one log_path many log_formats

[lebinh]

thanks @FEIGONG, can you have some summary of this changes or break this down into smaller PR so it'd be easier for me to review and merge them?

[Oh-Little-Papaya]

fix bug when tap commands like 'ngxtop' or 'ngxtop info'

[Oh-Little-Papaya]

@lebinh OK ,I will think how to break these pr into smaller pr

[lebinh]

That'd be great! Thanks @FEIGONG