JavaDoc on Graph.configuration().
Changed method signature of Property.element() to simply return Element.
Merge remote-tracking branch 'origin/master'
Fix profiling for MapStep
added Reducing marker, ReducingStrategy, and now FoldStep have a correlate in OLAP when it is an end step. Fixed #273
updated docs and made it so DedupStep implements the new Reducing marker interface.
updated docs and made it so DedupStep implements the new Reducing marker interface.