GSF.TimeSeries: Added comments to MeasurementKey describing the reasoning behind SyncEdits.
GSF.TimeSeries: Added comments to MeasurementKey describing the reasoning behind SyncEdits.

git-tfs-id: [https://tfs.codeplex.com/tfs/TFS07]$/gsf/Main;C94375

GridProtectionAlliance/gsf,rmc00/gsf,GridProtectionAlliance/gsf,GridProtectionAlliance/gsf,rmc00/gsf,GridProtectionAlliance/gsf,rmc00/gsf,GridProtectionAlliance/gsf,rmc00/gsf,GridProtectionAlliance/gsf,rmc00/gsf,GridProtectionAlliance/gsf,GridProtectionAlliance/gsf,rmc00/gsf,rmc00/gsf