Added notes from the last meeting.
Added a function to generate a DOT file from a generic LTS.
Minor addition to .gitignore.
Working on making a module to represent a ZVG as a module.
Deleted a long comment.
Shifted some computation around, so that we now have zones in the zone
valuation graph (I know how it sounds) but only thise zones that are
actually reachable and only those which appear after transitions which
are actually doable.
Made ZVG compatible with LTS. Will merge now.