OpenTSDB: Clean up and error handling for bulk put. (https://rbcommons.com/s/pepperdata/r/4320)
- CompactionCB calls completion callback with exception when there were any
errors. - addPointList replaced ConcurrentHashMap with ByteMap. So, there is no
reason to compute the hash key for a row (key). - Other cosmetic changes to
address most of the comments at https://rbcommons.com/s/pepperdata/r/4275/.