this includes:
- Add Accumulator to the Start() function of service inputs
- For message consumer plugins, use the Accumulator to constantly add
metrics and make Gather a dummy function
- rework unit tests to match this new behavior.
- make "flush_buffer_when_full" a config option that defaults to true
closes#666
This constitutes a large change in how we will parse different data
formats going forward (for the plugins that support it)
This is working off @henrypfhu's changes.
Cameron Sparr
Jack Zampolin