Blender Git Loki

UI: Add margin to panels

Add some breathing space between the panel boundaries and properties/regions.

Make use of the style->panelouter property that hasn't been used in a while.
Also slight tweaks to boxspace and templatespace style properties so they
are multiples of 2 and operations on them round better.

UI: Disable emboss on box widgets

These are meant to be contour for an area flush with the background,
having emboss hardcoded on the widget prevents this.

Fix stack buffer overflow asan warning

UI: Fix dark and light themes

Mainly so it doesn't look broken to people testing out the branch, namely
the background of radio buttons was pure white, and separator in menus pure black.

Also minor tweaks to the default theme.

UI: Use rounded corners for panels and subpanels

UI: Separate each choice inside radio buttons

Add some room between the choices. This way we can give the background and
non-active options the same color and make it look more like only one choice
can be active at a time.

This is in an effort to make the radio buttons and toggle buttons look different.
Currently in Blender they looked the same even though radio buttons only allow
one active option at a time, while toggles can be have multiple.

UI: Make use of menu item theme roundness

Use theme preference instead of hardcoded square corners.

UI: Use Outline color of menu item for separator

Instead of forcing a transparent shadeof the text color.

UI: Adjust outline color of active default buttons

Simply darken slightly the already used outline color. On light themes it prevents too bright outlines on hover.

UI: Support alpha in Value Slider widget

The alpha value was being ignored even though the item property could be set.

UI: Do not rotate vertical scale indicators

In animation editors with vertical scale indicators, such as Graph Editor
or Drivers, display the values aligned to the view.

UI: Improve contrast on playhead

Add a dark (background coloured) outline around it.

UI: Use arrow icon to collapse/expand panels