Implement lifecycle logging

[keith-turner]

Following the lifecycle of certain events in Accumulo via documented logical loggers would be really nice. For example it would be nice to be able to follow the lifecycle of a write ahead log across the master, tserver, and GC using a logger name like org.apache.accumulo.log.wal that does not correspond to any class. These logical loggers could be documented in the Accumulo user manual, like Fluo does.

Could have life cycle logging for the following events to start with

• Write ahead logs
• Tablet events (like assignment, loading, compaction, scan, update, unload, recovery, etc). All tablet events could be logged under org.apache.accumulo.log.tablet. Something like scan could be logged under org.apache.accumulo.log.tablet.scan at trace allowing a user to turn on trace scanning for scans only.
• FATE operations like bulk import could log everything related to bulk import in client, master, and tserver under org.apache.accumulo.log.bulk.

One way to implement this would be to create class with static methods for each life-cycle we want to log. For example all logging of tablet lifecycle events would be done in a single class via static methods. The advantage of this approach is that it brings all of the logging together in one place in the code which will lead to more consistent log messages.

Most existing log messages should not follow this approach.

[keith-turner]

Could use much shorter logger names like accumulo.tablet and accumulo.wal like Fluo does.

[keith-turner]

In addition to documenting the loggers in the user manual, it would be nice to create a schema for these log events that could be used by log stash apache/accumulo-fluo-muchos#254

[EdColeman]

I'm interested in taking a run at this as well as #1249 - not assigning myself at this time in case other events delay me in starting to work the issue(s)