This extends the libdivecomputer notion of "dc_tankvolume_t" to not just
have the tank volume type (imperial or metric), but be a "dc_tankinfo_t"
that shows other information about the cylinder.
The imperial-vs-metric data remains the same two values:
1 - metric
2 - imperial
but instead of being an enumeration of volume types, it is extended to a
bitmap of tank information, and the other bits currently are
4 - CC diluent cylinder
8 - CC O2 cylinder
with possible future extensions (bailout gas, perhaps).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
167848aa59