gas tracking progress

[Dirk Hohndel]

Our gas tracking in the planner was broken on several levels.

I have just pushed out a couple of commits that make it somewhat better

I still haven't addressed the odd initial gas change / gas name shown
issue when you start with a different gas than gas 0. So that remains on
my todo list. But at least we should now get the gas amounts used more or
less correct - even if you have a gas that has no real cylinder associated
with it.

Please test and find the bugs I have carefully hidden :-)

/D