numixproject/numix-gtk-theme

Since Xfwm have never expressed much interest in virtual resize
grips extending away from the window area, and need to support non-
composited configurations anyway, this usability fix is needed in
Numix. Single-pixel borders are not enough.

This commit adds a 5px bottom border and big corner resize grips to
Xfwm allow windows to be resized more easily. This improves matters
significantly for tablet and mouse/touchpad users.

The corner resize grips are from NeXTSTEP, or more accurately its
clones on Linux such as Window Maker. The bottom border as a whole
is styled to match the rest of the theme.

Closes numixproject/numix-gtk-theme#100.

…ixes #675

…ixes #480

Looking at https://www.archlinux.org/packages/?q=numix ,
I don't see any `numix-themes` package, but a `numix-gtk-theme` one.

* Do not draw progressbar border using box shadows, progressbar is now more flatter.
* Do not use different color for progressbar in disabled state. In transmission, in normal state, progressbar (not selected)
has no color, while in backdrop state it gets it's color back. This shouldn't be happenning.
* Use border for progressbar.through

These fixes are mainly for light variant. Dark variant requires much more work.

We were drawing border on both notebook tab
and on widget > box, which results a double border on tab. The situation
worse in case of tiling gtk3 apps like tilix which uses can use horizontal
notebook inside vertical notebook.

Separate mixin for toolbar and titlebar
Symbolic icon for horizontal toolbar. Lets face it, toolbutton icons for gnome+hicolor are not as good as symbolic icons. We are using symbolic icons everywhere else anyway.
Button padding for horizontal toolbar is reduced to 4px. Horizontal toolbar requests GTK_ICON_SIZE_LARGE (24x24) by default. It doesn't make sense to use 5px padding on 24x24 icons.
Button (image, text, image-text, popup, radio) padding for vertical toolbar,headerbar remains same for now.

Still not perfect
More will come once I unify button (image, text, image-text, popup, radio) paddings

…#498

…ht variant

checked stated background color is too dark and text is not readble in backdrop state. This fixes the issue.