Spiked the idea of a reset() method on the Pipe interface.
Missed resetting AbstractPipe state.
missing import after rebase
Missed a variable when resetting AggregatorPipe.
Some reset tests.
RangePilter and VertexEdge test
Add reset to AbstractEdgesPipe
Reset in aggregator pipe.
Test reset on count and groupcount.
Test reset on scatter pipe.
Test reset on SideEffectCapPipe.
Allow PropertyPipe to work either with or without returning nulls.

includeNull == false would be very useful in a future filter pipe for instance.
Added an option to turn the future filter pipe negative.
Merge branch 'feature/reset' into develop

* feature/reset:
  Test reset on SideEffectCapPipe.
  Test reset on scatter pipe.
  Test reset on count and groupcount.
  Reset in aggregator pipe.
  Add reset to AbstractEdgesPipe
  RangePilter and VertexEdge test
  Some reset tests.
  Missed a variable when resetting AggregatorPipe.
  missing import after rebase
  Missed resetting AbstractPipe state.
  Spiked the idea of a reset() method on the Pipe interface.
Added HasCountPipe which returns true only if a pipe has within a given range of number of elements.
Enable the HasNextPipe to be used by adding it to the end of a pipe.
Test the HasCountPipe.
Test reset on HasNextPipe.
removed deprecated VertexEdgePipe and EdgeVertexPipe for new OutEdges, InEdges, OutVertex, etc. pipes.
added copysplit, exhastivemerge, and fairmerge pipes. Added metaPipe interface and propagated its implementation to all pipes where it makes sense.