[LOGGER] Switch to built-in logging class

[LOGGER] Switch to built-in logging class

Switch from the homegrown RarslaveLogger class to the built-in logging
class. Convert all code that used RarslaveLogger to use the logging class,
and remove the RarslaveLogger class completely.

Signed-off-by: Ira W. Snyder <devel@irasnyder.com>