Sanity check on temperature values

The range is still very wide (as we get both air and water temperatures),
but it will at least eliminate some completely bogus outliers.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Use information from proper table on DM4 import

Seems that DM4 has useless cylinder size data on global level and real
data on DiveMixture table. So using the correct data instead of the
global un-used value.

Similarly the DiveMixture table contains cylinder pressures. However, it
appears this information is available on DiveMixture table only in some
cases. So we use start and end pressures from DM table if available,
otherwise we use the global pressures. (My guess is that the DM table
has the pressure info only when the pressure has dropped from the
initial pressure reading that is reported in Dive table before the dive
is considered to have started.)

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>