Added (create/extract)updatePayloadBuffer functions.
Added (create/extract)updatePayloadBuffer functions.

mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite,8l/Graphite,mit-carbon/Graphite-Cycle-Level,8l/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite,nkawahara/Graphite,mit-carbon/Graphite,8l/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,fhijaz/Graphite,nkawahara/Graphite,8l/Graphite,nkawahara/Graphite,victorisildur/Graphite,victorisildur/Graphite,victorisildur/Graphite,fhijaz/Graphite,nkawahara/Graphite,mit-carbon/Graphite,victorisildur/Graphite