Need to add DEBUG/INFO/WARN/FATAL specific logging in the new driver.

Generic Operation Logging.
Events fired for each.
Hooks for Instrumentation (New Relic).

DEBUG:

• Query with RTT
• Command with RTT
• Map/Reduce with RTT
• Aggregation with RTT
• Bulk Delete with RTT
• Bulk Insert with RTT
• Bulk Update with RTT
• List Collections with RTT
• List indexes with RTT
• Get More with RTT
• Insert with RTT
• Update with RTT
• Delete with RTT
• Create User with RTT
• Remove User with RTT
• Ensure Index with RTT
• Drop Index with RTT
• Insert file into GridFS with RTT
• Find file in GridFS with RTT
• Remove file in GridFS with RTT

INFO:

• Server added to cluster.
• Connection added to pool.

WARN:

• Server description change.
• Server removed from cluster.

FATAL (do we even want fatal logging or should we be raising exceptions for all?)