Blender Git Loki

UI: Particles improvements

* Icons in specials menu (Copy and the new Duplicate icon)
* Remove redundant "Settings" label next to ID template widget.
* Remove "Type" label and expand dropdown, since it only has 2 options (emitter/hair), saves 1 click.
* Move "Seed" to and "Hair Segments" to Emission panel
* Rename "Duplicate Particle Systems" to "Duplicate Particle System", since it
only duplicates one (the active one) at a time.

UI: Detach Material specials menu from add/remove column.

Eevee: Implement Overscan option

This option make the internal render size larger than the output size in
order to minimize screenspace effects disapearing at the render edges.

The overscan size added around the render is the maximum dimension
multiplied by the overscan percentage.

UI: tweak usage of duplicate/add icon for consistency.

Still difficult to know when exactly the operator will duplicate and when
it will add a new one. Some open a menu with different choices too.

UI: Small tweaks to Shape Keys/Vertex Groups menus

Mainly added separators to the Vertex Group/Shape Keys specials menu,
separating items by type and removing redundant icons for better readability.

Allow changing B-Bone custom handle references from Pose Mode.

@jpbouza was rather upset these were made read-only, and unlike
parents, it's not that hard to allow changing these Bone fields:
all is needed is to carefully refresh the matching fields in the
relevant bPoseChannel objects and properly tag update.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D3870

UI: icon set updates by Andrzej Ambroz.

New icons for duplicate, driver types, window, hue/saturation.

UI: more single column layout for brush and render properties.

OpenSubdiv: API, expose vertex boundary interpolation option

Only affects internal API, bout could be exposed as an option for
the compatibility reasons with other software.

Is a part of some ongoing development of multires, but might or
might not be used.

disabled a verbose print when using many objects

GP: Fix icons

GP: Move Autlock to Layer menu

Image Empties: More visibility settings

Support for showing images in background/foreground and only in perspective/orthographic view.

Internally the depth of the image is modified in the fragment shader by setting `gl_FragDepth` explicitly.

The UI still needs some work to improve usability, see D3863 for details.
Currently there is one duplicated function, not sure how to best deduplicate it yet. (`is_image_empty_visible`)

Reviewer: fclem, brecht, campbellbarton

Differential Revision: https://developer.blender.org/D3863

Expose full ID name in RNA as well.

That way scripts can have a consitent way to get unique ID key/string,
and can use it for access in bpy.data collections as well.

Note that this kind of douples the old py API way of doning this
(passing tuple of (ID-name, lib-path) instead of just ID-name).

Make new library IDs named from the .blend file.

Now that we do use that ID name of them in UI sometimes...

UI/Unique ID name: add library ID name if present.

Also reshuffle a bit that whole code, did some renaming,
`BKE_id_to_unique_string_key()` is now using same base code (instead of
using whole library filepath...), etc.

UI: Move Color Management panel from Scene to Render properties.

It makes more sense to have Color Management under Render properties,
even though they are per scene (so are render dimensions anyway).

Eevee: Fix dot corruption on intel HD5xx/6xx series

It is caused by some sync issue apparently. Adding glFlush in these
two places fixes it.

Caveat: it might have a small perf impact (did not measure it).

The fix is limited to the affected driver/operating systems.

GPU: Add glFlush and glFinish wrapper

Merge branch 'master' into blender2.8