Implement CLI options for logging destination, level

[stratofax]

Currently, logging is set in this app's entry point (cli.py) as follows:

logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)

This is useful for debugging, but not appropriate for production code. These default values should be re-evaluated when it's time to ship -- most likely, something like this:

stream=sys.stderr, level=logging.ERROR

In addition, the CLI (and settings file, when it exists) should allow end users to set:

• the logging level they'd like to use
• the output destination (stdout or a specific log file, for example)

Since these options control how "verbose" the output is, we either:

• don't need a "verbose" option
• could use "verbose" as a logging preset -- for example, set logging level to INFO and all notifications to stdout