fixed bug where GiraphGremlinPlugin was still named 'giraph'. Made it so that ExpandableIterator is about getting single objects vs. iterators so we don't have this aggregation behavior. My solution needs to be expanded on as its a bit ghetto, but it works. Fixed #220.
Update changelog.
Modified the manner in which OptOut annotations are validated to be more robust.

No longer limited to just structure tests.  No longer implemented as a unit test that can't be opted out of.  It is built directly into the validation of the the implemented test suite making it easier to centrally enforce.  Provide better error messages to implementers so that it's clear about what needs to be fixed.
Add EdgeFeatures.supportsRemoveEdge.
Step now has .addStart(Traverser) and .addStarts(Iterator<Traverser>). Lots of places where SingleIterator existed that caused unecessary object creation. However, we can't go full .addStart(Traverser) as if you pass an iterator, we need to be lazy about it. Its a balance btween TraverserSet (greedy) and Iterator (lazy). I will be reworking ExpandableStepIterator to make it good -- current impl is weak.
Fix RangeStep
Merge branch 'master' of https://github.com/tinkerpop/tinkerpop3
added doc on RangeStep and tweaks to ExpandableStepIterator.