Planner: fix incorrect gas change event

We stored the He permille instead of the He percentage. But for most
casual testing this was hidden by the previous bug.

Reported-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Documentation: Updated "Edit Equipment Info"

- More lists converted into tables.
- Minor changes to text.

Signed-off-by: Reinout Hoornweg <reinout@xs4all.nl>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Makefile quorks :( Yes we want a 'doc' target for itself...

...to avoid generating the HTMLDOC target even if it needs not to.

Signed-off-by: Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn@axis.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Documentation: more tables in "View Info & Stats"

- Even more tables.
- Renamed the chapter to "View Dive Info & Stats" because one of the
  tabs being described is named "Dive Info" and not "Info".

Signed-off-by: Reinout Hoornweg <reinout@xs4all.nl>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix tracking of selected dives across sort column changes

With  commit 800b0482f39e ("When switching sort order, scroll the dive
list to the current dive") we introduced an unwanted new behavior. When
changing sort columns we could lose all selections except for the main
"selected_dive". This was caused by the call to gtk_tree_view_set_cursor
on the selected_dive which unselected all other dives.

As a side-effect this also fixed another bug that was introduced by the
same change: shift-cursor-up and -down now works again to select multiple
dives with the keyboard.

But fixing that bug unearthed a different issue. Our code that restored
the selection state of the tree model oddly decided to mark a divetrip as
selected if its first child was selected. The bug above masked that by
immediately unselecting the trip again, but now that this was fixed the
problem was immediately obvious: we would start with both the first trip
and the first dive in that trip selected (well, since we are in reverse
order it's actually the chronologically last trip and last dive...).

Instead we now use the remembered state of the trip to determine whether
it should be expanded or selected.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Preserve keyboard focus when changing sorting order in the divelist

When the user changes the dive list sorting order via clicking
on different column titles, using gtk_widget_grab_focus() gives
keyboard focus back to the list itself (not staying on the column titles),
which gives a hint that the list itself has focus index of 0 and is
reset each time the widget receives this type of "initial" focus.

Acked-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Indicate to the user a default divelist sorting order

Each time subsurface starts there is supposedly no sorting order
(or divelist column) specified by the UI, yet the actual column is '#'
(or dive number column), since its the *only* column which allows
trips to be visible. If the user selects a different sorting order
then he has no idea which column was the one who had the trips visible.

"Where did all those 'trip' things go?"
This can be a bit confusing...

Lets provide indication by calling gtk_tree_view_column_set_sort_indicator().
Also call gtk_tree_view_column_set_sort_order() to specify a descending
order.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>