Switch bitbake internals to use logging directly rather than bb.msg

Switch bitbake internals to use logging directly rather than bb.msg

We use a custom Logger subclass for our loggers

This logger provides:
- 'debug' method which accepts a debug level
- 'plain' method which bypasses log formatting
- 'verbose' method which is more detail than info, but less than debug

(Bitbake rev: 3b2c1fe5ca56daebb24073a9dd45723d3efd2a8d)

Signed-off-by: Chris Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>