Add Tango and Adwaita icons for the toolbar

[Yuan Fu]

Hey guys,

I followed the original tool-bar icon thread in 2022. At the time I didn’t have 
much time and I personally prefer colorful icons for the tool bar [1] (IMO 
mono-colored symbolic icons are more suitable for inline, small icons), so I 
didn’t do anything except for observing the discussion. 

[1] I especially adore the life ring icon for help! Whatever icon set we use 
for the tool-bar, the help icon should always be a cute life ring :-)

The recent Emacs app icon thread reminded me of that thread, and I do have time 
now. So, I went ahead and searched for the Tango and Adwaita icons (basically 
the high-res version of the existing tool-bar icon that we use), then converted 
them to be suitable for Emacs tool-bar.

About 1/3 of the icons can be directly taken from Tango or Adwaita, the rest I 
have to modify or kind of take apart and re-assemble. Anyway, in the end I 
managed to get most of the basic icons covered. For details see 
etc/images/scalable/README.

You can see the attached screenshots for the current built-in icons and the new 
icons. I also attached the patch for it. You want to rebuild or byte-compile 
tool-bar.el for the new icons to take effect.

I hope these new icons won’t be controversial. As you can see, they are 
basically straight high-res upgrades for the existing icons. There are many 
imperfections that’ll be atrocious in the eyes of a graphic designer—I did the 
conversion work in an afternoon and I’m no where near a graphic designer; but 
it’s definitely an upgrade and we can always incrementally improve after.

If no one objects, I’ll happily push this to master.

Yuan

tango-icons.patch
Description: Binary data