Handle illegal variable names
PseuCo is very lenient with variable names, e.g.
_ is legal. Since
colored-petri-nets is more strict (and rightly so), we need consistent renaming (probably mediated through
scope). To allow the pseuCo debugger to retrieve variable names, the renaming needs to be described in the net (likely per place to handle local variables).
Original issue: concurrent-programming-web#59