#225 enable logging to different streams

1st step for #225 enable logging to different streams. The next step is to support application history based on this work.

Please first review this work.

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1. good point. will rename it.
2. as we need to keep a hierarchy structure for application/container, I prefer to use two property instead one so that we don't need encode/decode these two ids. So, I prefer to keep current two properties.