Correctly parse the braindamaged tank size information from uemis

Correctly parse the braindamaged tank size information from uemis

Admittedly the cuft ratings are stupid, but still, it's not that hard.
In order to correctly describe a tank based on the cuft system you need to
know the cuft AND the working pressure. But the uemis Zurich always
assumes that the working pressure is 200bar. That's pretty close to
3000psi and therefore works "good enough" for Aluminum tanks - but in
general this will of course fail (e.g. for HP or LP tanks).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>