Adjust logging levels and usage to follow standards

A few of our logging levels and messages should be
updated to better reflect the oslo logging standards
created at https://wiki.openstack.org/LoggingStandards
so update some of them to not report error when its really
warning level and not report warning when debug is better.

Change-Id: I8abdb1bcfa2893c6b97eda7e85ac779e456966b8
Small documentation fix

Change-Id: I31959cd9ea0465bf9aabb3a222cb45630cde8f66
Merge "Small documentation fix"
Merge "Adjust logging levels and usage to follow standards"