fiexd. #1

Summarize the Postfix log in qid unit.
fixed. #2

It was modified to delete the old buffer.
fixed. #3

Write the buffer at the time of stop.
Read the retracted buffer at startup.
fixed. #4

Add config param `clean_interval`.
Add config param `survival_time`.
fixed. #5

Add config param `start_sent_time`
Add config param `end_sent_time`
Merge branch 'develop'