Blender Git Loki

Redesign area/region edges

Mainly removed unnecessarily drawn edges and doubled line thickness for
area edges to clearly separate areas from regions.

For now I've added a theme option to control the color of the area
edges, we can check later if it's worth keeping it, but IMHO it's quite
important to have this controllable.

Don't draw widget outlines (for most widgets)

As proposed in T38037 this removes the outlines from widgets (except of
toggle buttons like layers and color buttons for now) to simplify/
flatten the look of the UI.

This needs some more polish and we could even remove the outline drawing
code completely instead of just disabling it, but I first want to get
overall design approval.

Increase default DPI to 78, decrease default font sizes to 10

NOTE: These changes might be controversial, but it's a good chance to
test this.

Also further changes to default font drawing plus a bit of cleanup.

Flatify the UI!

By disabling shaded drawing for all widgets

Make scrollbars thinner! (And draw them without outline)

Scrollbars with units printed on them stay the same size.

Merge branch 'master' into UI-graphical-redesign

Redesign panel headers + minor tweaks + minor cleanup

Currently looking like this: https://developer.blender.org/F183457

Design was worked out together with @plyczkowski

Panel mouse hover feedback

* Highlight hovered panel
* Only draw drag widget on hover

Some cleanup to make code a bit easier to read ;)

Adjust new panel design to work fine with recent panel drawing fix

Merge branch 'master' into UI-graphical-redesign

Remove panel emboss

Don't like it after using it a bit :S

Merge branch 'master' into UI-graphical-redesign

Conflicts:
source/blender/editors/interface/interface_widgets.c

A first panel redesign

Looking like this now: https://developer.blender.org/F182118

Based on this mockup by @venomgfx: https://dev-files.blender.org/file/
data/sgkm33r4yxspq3gzy2dl/PHID-FILE-xzedfbwhq5tdx4w7jgcw/
blender_ui_drag_widget_gone_padding.png

Theme option to change widget corner roundness (per widget type)

Original patch by @venomgfx, updated and made a few minor changes.

Merge branch 'master' into UI-graphical-redesign

Make checkbox widgets rounded