Log events sent to CloudWatch should use timestamp parsed from log

[andeero]

When log events from agents are sent to CloudWatch, the current time is used for the InputLogEvent object. There may be a considerable difference between the time of the actual log event and when the event gets sent to CloudWatch. This leads to inaccurate timestamps in CloudWatch Logs.

E.g:
2016-06-08 10:26:28 UTC 12:23:34.552 [pool-1-thread-4632] TRACE n.c.j.e.CommandExtractEventsFromFile - Line 6621 was the last line read from file=logs/jau.log

Possible solution:

• Extend eventExtractionConfig with timestamp format
• Parse timestamp according to format
• Fallback to current time if parsing fails?