Moved NodeObservable to shape
Renamed shape package to node
Removed shape stubs
NodeMarble is a Node, not a shape
Description NodeOperator
NodeObservable constructor is public
Depend on java-util for Optional
Cleanup MarbleUI imports
GhostMarble doesn't need to know what obs it's on
Renamed GhostMarble to NodeGhostMarble
NodeSimpleMarble not aware of a model for now
NodeMarble extends group, was node
Use translate to move Ngon(simple marble)
Simple marble exposes it's line to subclasses
GhostMarble as a SimlpeMarble
Use properties for ghost/marbles in NodeObs