## About The Pull Request
Adds defines for gasses and replaces uses I've found to instead use the
defines.
Can you believe I made this PR while trying to work with Xenos? This
sucks!
## Why It's Good For The Game
There's a lot of different uses of things like "o2" and "plasma", and
they are pretty inconsistent. In some places, it's "hydrogen", in others
it's "h2". In some it's "plasma", others "plasm". This unifies it all
under defines so it has a less chance of breaking in the future.
## Changelog
Nothing player-facing.
0c99bd28f4