Include other stock fuels in delta-v calculation

[ElWanderer]

Our delta-v calculation assumes that everything burns liquid fuel and oxidiser, which is unhelpful if we want to power a vessel with an ion engine, monopropellant engine or solid rockets (though that's only really an issue if we're printing out the current delta-v a lot e.g. if we add a GUI with a delta-v display). It could also return the wrong answer if we have only nuclear engines, but happen to be carrying oxidiser.

Unfortunately, the only way I'm aware of implementing this is to have a lexion of "unusual" engine names and the fuels they use. Everything else can be assumed to use liquid fuel and oxidiser. Any mod parts that don't use liquid fuel and oxidiser would need adding to this list.

As with issue #121, it would be good not to have to keep checking what engines are available each time we want to know the delta-v - we can set this up on initialisation and update it whenever we stage.

[ElWanderer]

We could add non-stock fuels at some point, but that'd probably best be raised as a new issue