Allow clang++ to be used for compilation by setting a shell variable
More warning cleanup from 64-bit clang
Tweak clang warning settings
Pull out bionics activation into helper functions

The length of that function was ridiculous. Now at least the open and close braces are close enough for my editor to match them.
Unify bionics liquid handling via another helper function

Extracted common code from the two water-producing bionics into its own helper function.

Slight behavior change: water extractor now produces clean water. Probably intended behavior anyway?
Document bounds of rng()