Refactor logging implementation

[numbat]

Do we need the logging at all?

[rzhilkibaev]

Did you want to say 'Do users need the logging at all?'? :)

[myuwono]

There's this awesome blog post that captures my mixed feeling about logging from within library code. I vote for either minimal or nothing at all:

http://pythonsweetness.tumblr.com/post/67394619015/use-of-logging-package-from-within-a-library

[myuwono]

I'm removing LogMixin for now