in, out: new impls
remove or replace all super calls
GremlinScalaPipeline does not inherit GremlinPipeline any more. benefits
e.g.: 
methods like filter etc. won't have to declare the type anymore:
currently it's pipe.filter{v: Vertex => true}, then it can be:
pipe.filter{v => true}
move tests that currently don't work away ;)
remove implicit cast
clean up imports
always doQueryOptimisation
use ScalaVertex
get TraversalStepsTest back to live
using ScalaVertex/ScalaEdge everywhere was a dead end. Relying on
implicit conversion only when necessary now. Additional benefit: no need
to wrap all the time.
bring tests back in
make Graph.v return a Vertex, as except and retain make more sense that way
remove [_] which was only used as a trick to override methods
upgrade to scala 2.10.3
addPipe2 -> addPipe
rename toScalaList -> toList
provide a named method for startPipe, use Edge rather than ScalaEdge
use label, not getLabel
remove filterPF
remove filterNotPF