Blender Git Loki

Eevee: add Principled Volume shader.

Eevee: add blackbody shader node support.

This replaces the blackbody to RGB code with the simpler and faster one from
Cycles. It's a little different but the other placing using this is the legacy
volume drawing, so no need to stay compatible with that.

GPU: fixes for string socket types in shader nodes.

These are not passed to GLSL functions, but should be used to load e.g.
a texture or attribute.

Eeevee: add temperature grid support, make color grid unpremultiplied.

This matches similar changes done for Cycles.

Merge branch 'master' into blender2.8

Cycles: add Principled Volume shader.

Similar to the Principled BSDF, this should make it easier to set up volume
materials. Smoke and fire can be rendererd with just a single principled
volume node, the appropriate attributes will be used when available. The node
also works for simpler homogeneous volumes like water or mist.

Differential Revision: https://developer.blender.org/D3033

Cycles: change smoke color grid to not include density multiplied in.

This breaks backwards compatibility some, making smoke colors brighters
than before. But it is also more correct this way.

Code refactor: improve attribute handling for optional volume attributes.

A volume shader should be able to request attributes, and still be rendered
as homogeneous if no volume attributes are available for the object.

Smoke: change default flame temperatures to match OpenGL preview.

Smoke: add temperature grid, with values 0..1 corresponding to 0..1000K.

Nodes: left align text for color and string sockets, same as other types.

Fix border rendering for eevee + stop passing render result around

Technically the original issue is that xof/yof in render result is calculated
for drawing border render. So a simpler patch could be:

```
- rr->xof = re->disprect.xmin;
+ rr->xof = re->disprect.xmin + BLI_rcti_cent_x(&re->disprect) - (re->winx / 2);
```

However everywhere in the code we are getting border directly from re->disprect
which we may as well do here too.

Besides I'm taking this as a chance to get rid of RenderResult in the internal
loop of eevee, to help prepare the code to the upcoming rendering pipeline
changes.

Fix T54137: OpenEXR files with long red/green/blue channel names not loading correctly.

Buildbot: Enable Volta deviced CUDA binaries

Buildbot: Remove master configuration files

Those are stored in blender-buildbot repository now, so having them in
Blender only causes extra work to keep files in sync.

Buildbot: Disable cuda hack for macOS

Merge branch 'master' into blender2.8

WM: Add WM_menutype_poll function

Wraps menutype poll, no functional changes.

Merge branch 'master' into blender2.8

WM: add WM_keymap_poll function

Wrapps keymap poll, no functional changes.