removed q.contains again. causes duplicates

to 22 lines in output.txt
Determine cause why.
cause determined, reverted to best code.

Upon further review I've concluded why now. The containment checks
against both queues are necessary, since essentially both queues serve
as lists of for TO VISIT (q) or HAVE VISITED (v). As such, generally
every node should at maximum be marked TO visit once only, and at
maximum BE visited once only. Furthermore it makes no sense to exist in
both lists / queues simultaneously.

My issue was I hadn't clearly defined the purposes of q and v
previously. I simply had determined I needed a second queue after
starting with the first.