New icons

[Martin Měřinský]

Hello,
I've been working on icons cleanup and got to the point, when it's
usable. I would like to present you some screenshots.

Why I did that?

* Icons were in several formats, and several sizes. It made them
diffucult to work on. Now all icons are scalable. Bitmap icons can be
fine-tuned for several sizes (but SVG works just fine for me). Scalable
icons are also usable for HiDPI displays.

* Filenames were mess. Now all filenames follow one naming scheme.

* Some Subsurface icons were arranged to a theme, some not. Now all of
them are. It makes it possible to use your current theme icons and
improve yout GUI integration (or switch icons theme).

* Number of icon files has decreased. Icons have been deduplicated and
unused icons were removed.

For graphics: SVG files are using correct 96 DPI. "Plain SVG" format is
used. It makes files small. And there are less binary files in the
repo.

What changed?

* While many icons have to be drawn from scratch (there weren't SVG), I
tried to find better metaphors and improve icons readability. Please
consider this a proposal. Once SVG icons are used, it would be much
simpler to improve (redraw) icons. I'm open to suggestions.

* On several places, your GUI theme icons are used. I believe this is
the way to go.

* I changed very slightly buttons order. I followed general rules:
* Related items close to each other.
* Most important and used items first.
* Ceiling options are somehow likely to be found up.
* Bottom options should be down (where one expects the bottom).
Proposed order is:
* Start with various ceilings.
* Gas related items and partial pressures.
* O2 limits us the most, then N2, He only TECs.
* Divers body related items. Both are rates.
* Depth limit related items are down (NDL is closely related to
depth).
* Graph related options last.

* If there is no graph to show. Scale background Subsurface logo.

* Filter show/hide icon changes according to the action it will
perform.

I tested only Linux + Gnome. I hope MacOs and Windows would work as
well. I didn't test mobile version, because I'm not using it. I tried
not to break it.

Please, see attachement. Note these changes:
ss1
* New buttons icons.
* Dive profile buttons order slightly changed.
* Background logo scales.
ss2
* Preferences icons are used from GUI theme (except Units, Profile,
Georeference).
ss3
* Instead of arguable quality photos, images.
ss4
* Filter visible. Clear and close buttons icons from GUI theme. New
hide icon.
ss5
* Filter hidden. Show button icon changed.
ss6
* List add and remove icons from GUI theme.
* New dive bookmark icon.
* Map icons with greater difference between selected and non-selected
locality.
ss7
* New icons for minimum, average and maximum value.

You are welcome to test, or merge ;-) the code.

Thanks in advance.
Martin MěřinskÃœ

[Henrik B A]

I will admit that I feel many of the new icons aren't as nice as the old
ones.
They feel "blocky" and "old" to me.
Obviously I'm not a graphic designer and I'll be the first to admit that
I'd have
ZERO talent to do any better - but after coming back to this email and the
screen shots a few times... I'm not in love with the new look.

I wanted to chime in here as well. Unification of icon names and other
changes here: very cool. Should be put in a separate PR.

But many of the new icons feels bulky, cluttered, and less clean. E.g. the
he/O2/n icons have some arrows (?) in the corners that I don't understand.

Henrik