Refactor FakeLogger into a PrintingTestLogger and a CapturingTestLogger
Fix report of leaked memory during UTs by making the default logger static, and exclude a line from coverage
Merge remote-tracking branch 'origin/master' into fake_logger
Correct member visibility
We don't use #pragma once
Lock when changing a logger or writing to the logger, to avoid race conditions when the statistics thread is logging as a logger is being destroyed.
Code coverage exclusion
Code review feedback, including enforcing RAII
Merge commit 'c277184' into fake_logger
Make it compile
Merge remote-tracking branch 'origin/master' into fake_logger
Merge pull request #120 from Metaswitch/fake_logger

[Reviewer: Andy] Rework the fake logger used in UTs