Turn off Pi-Nodes

Not sure of the real benefits of this and it might be easier to just turn
it off for now to simplify the analysis.

See #1.
Update the name from ghostView to pdf

No need to use the antiquated name since we cannot support ghostview
anyway.

See #1.
Maps the def-use of each SSAInstruction to the local variable name

This makes it easier to see what is going on.

See #1.