Adjust logging to a more standard format

[wpears]

Have separate log levels which are adjustable via commandline
Don't report elasticsearch logging except in debug mode

[wpears]

Logging is still a bit weird. Going to switch to a single --log flag which adjusts internal log levels, only switching on ES logging if set to debug.

[hkeeler]

It looks like you can configure the ES client's logger to use other logging libs. They have a Bunyan example. Seems like it be pretty straightforward to make that work with Winston log levels.