deprecated DList.flatMap, using mapFlatten instead
changed DObject.join(DObject) to zip
Merge branch '0.7.0-kiama' of github.com:NICTA/scoobi into 0.7.0-kiama
removed the wireformat instance on DObjectImpl and DListImpl
introduced 2 new traits ValueNode and ProcessNode in core to avoid cyclic dependencies
Merge branch '0.7.0-kiama' of github.com:NICTA/scoobi into 0.7.0-kiama