new-node: fixing inheritance test for :left/:right

    Previously we tested if left or right were instances of 'node
    explicitly. Now it accounts subclassing 'node.
Moving from fiveam to fiasco
Fix empty-stack condition
Move to a one package per file style
Tree to dot-graph requires swank
Move stack tests to fiasco
WIP Redblack Tree
WIP Visualizer
Update asd file and style fixes