Create a class to store messages for event log

Create a Logger class that can store log messages along with their
timestamps.  These messages will then be added to an event log when they
are created for missing fans, for debug purposes.  Each message is also
logged to the journal.

The maximum number of entries to keep around is specified in the
constructor, and when full the oldest message will be purged when new
ones are added.  This number comes from a configuration option which
defaults to 50.

A standalone getLogger() API was also added to give the new object
singleton behavior, so the same object can be accessed from all classes
in an application.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I8d5ac137acb67bfe78609d02aaf59a01b03c5c8b
8 files changed