The user may modify the salinity by selecting a water type from the combobox.
The new datum does not replace the existing salinity value but is stored in a
separate variable within the dive structure. If the dc-based salinity is
overwritten, there is an exclamation mark next to the modified salinity value
to indicate that the salinity has been overwritten. The dc-derived salinity can
always be recovered by selecting the "use dc" option in the combobox.
Signed-off-by: willemferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
