dive site management enhancements (request)

[Miika Turkia]

I have just tested out companion app on iPhone and this brings a few
enhancement requests. Some of these might already have been discussed,
but with poor Internet and heavy diving I cannot keep up with the bit
life :D

- Allow editing of multiple sites on divesite management. E.g. when
selecting a few days worth of dives, it would be nice to be able to
add names to these all with one go, seeing all the selected dives on
divelist and switching between them. (I used the automated mode when
recording GPS coordinates.)
- Some indication of the coordinates available on the notes pane next
to the selected site name
- Possibility to clear added Location (e.g. first item on the list empty)
- I am not able to store trip location
- The order of the dive sites changes between saves on XML log
- When adding a divesite from the plus sign on notes, one has to
restart Subsurface for it to be added to the list of available sites
(and to actually assign it to the "currently selected dive")
- Segmentation fault when adding divesite from the divesite management
feature  - stack trace below
- Selecting coordinates from the map is close to impossible (at least
when on divesite management)

And one extra from DC download:
- When I first download from air integrated Vyper, and next from
Stinger (with no idea of cylinders), I get a bunch of error messages
"different number of gases (1) and tanks (0)", the order of numbers
might change occasionally. I assume there is one error line for each
downloaded dive.

miika

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Program received signal SIGSEGV, Segmentation fault.
0x000000000058f4d4 in LocationInformationWidget::acceptChanges (this=0x1521c20)
    at /home/mturkia/source/static/test/subsurface/qt-ui/locationinformation.cpp:70
70		currentDs->latitude = displayed_dive_site.latitude;
(gdb) bt
#0  0x000000000058f4d4 in LocationInformationWidget::acceptChanges (
    this=0x1521c20)
    at /home/mturkia/source/static/test/subsurface/qt-ui/locationinformation.cpp:70
#1  0x000000000059f1eb in LocationInformationWidget::qt_static_metacall (
    _o=0x1521c20, _c=QMetaObject::InvokeMetaMethod, _id=6, _a=0x7fffffffcf90)
    at /home/mturkia/source/static/test/subsurface/build/moc_locationinformation.cpp:153
#2  0x00007ffff2ddd9c9 in QMetaObject::activate(QObject*, int, int, void**) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007ffff36ac722 in QAction::triggered(bool) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#4  0x00007ffff36aee28 in QAction::activate(QAction::ActionEvent) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#5  0x00007ffff37b323d in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#6  0x00007ffff37b3454 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
...
---8<---