Add the Annotation class for storing global or timeseries associated notes.
Add TSMeta class for storing metadata associated with a timeseries.
Add UIDMeta class for storing metadata associated with metrics, tagk and tagvs
Add unit tests for the new classes
Thanks to Peter Gotz for Annotations, will add his GraphHandler code later on

Signed-off-by: Chris Larsen <clarsen@euphoriaaudio.com>