Calculate nitrogen and helium gas pressures for CCR after import from CSV

Currently the gas pressures stored in structures of pressure are
calculated using the gasmix composition of the currently selected
cylinder. But with CCR dives the default cylinder is the oxygen
cylinder (here, index 0). However, the gas pressures need to
be calculated using gasmix data from cylinder 1 (the diluent
cylinder). This patch allows setting the appropriate cylinder
for calculating the values in the structures of pressure. It
also allows for correctly calculating gas pressures for any
open circuit cylinders (e.g. bailout) that a CCR diver may
use. This is performed as follows:

1) In dive.h create an enum variable {oxygen, diluent, bailout}

2) Within the definition of cylinder_t, add a member: cylinder_use_type
   This stores an enum variable, one of the above.

3) In file.c where the Poseidon CSV data are read in, assign
   the appropriate enum values to each of the cylinders.

4) Within the definition of structure dive, add two members:
   int oxygen_cylinder_index
   int diluent_cylinder_index
   This will keep the indices of the two main CCR cylinders.

5) In dive.c create a function get_cylinder_use(). This scans the
   cylinders for that dive, looking for a cylinder that has a
   particular cylinder_use_type and returns that cylinder index.

6) In dive.c create a function fixup_cylinder_use() that stores the
   indices of the oxygen and diluent cylinders in the variables
   dive->oxygen_cylinder_index and dive->diluent_cylinder_index,
   making use of the function in 4) above.

7) In profile.c, modify function calculate_gas_information_new()
   to use the above functions for CCR dives to find the oxygen and
   diluent cylinders and to calculate partail gas pressures based
   on the diluent cylinder gas mix.

This results in the correct calculation of gas partial pressures
in the case of CCR dives, displaying the correct partial pressure
graphs in the dive profile widget.

Signed-off-by: willem ferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Start with 0 when computing maxdepth when fixing up

This is needed to get the correct maxdepth when replanning
leads to a shallower dive.

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix position and size of the Filter

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make invisible stars stand out less

As my wife kept pointing out for a long time, the greyed out stars
were heavier as images than the yellow selected stars. This patch
makes the grey stars semi-transparent.

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Acked-by: Andrea Fischer-Helling <andrea@fraufischer.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Improve selection behavior of the multi filter

Only dives that remain visible stay selected. And if all selected dives
are removed by the filter, pick a new selected dive.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Correctly unselect trips when dive list filters change

Oddly Qt left the trips selected (but all dives where unselected in the
UI). This got our internal state rather confused. With this change we
clean up that mess and go back to just having those dives that were
originally selected and are still visible show up as selected.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>