Bugfix: do not reset saturation on surfacing Commit 822416168585 introduced a subtle bug. On surfacing, the value of saturation was reset to 0. This is prefect proof why global data is a dangerous thing, and subtle changes can introduce seemingly unrelated bugs. While it would be much better to factor out as much as possible global data, the fix here does not do that. Simply, the bug is fixed without touching the rather complex gTissue_nitrogen_bar/gTissue_helium_bar handling. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>