Blender Git Loki

Alembic: addition of a simple logging class.

The idea is to have a system where we properly log error messages and
let the users know that errors occured redirecting them to the console
for explanations. This is only implemented for the exporter since the
importer already has similar functionalities; however they shall
ultimately be unified in some way.

Reviewers: sybren, dfelinto

Differential Revision: https://developer.blender.org/D2541

Merge branch 'master' into blender2.8

revert recent cleanup, keep useful changes

Don't want to annoy module owner.

What is kept:
- UI_view2d_scale_get with unused y scale
- corrected comment
- unsigned --> unsigned int

Fix rotation manipulators not clipping

Added new shader for clipping, also cleaned up rotation manipulator
drawing code a bit.
This code should be replaced by new transform manipulators soon, just
keeping this working in the meanwhile.

Fix blenderplayer compilation

cleanup

I started cleaning up UI_view2d_scale_get where the y scale was unused, then got carried away...

- for loop scope
- declare variables closer to where they are used
- move early exits closer to function start
- unsigned --> unsigned int

Collada export cleanup

fix: Collada export selected worked only for the very first export (needs further testing and cleanup, see comments)

Immediate Mode: handle other cases of glPop/glPushClientAttrib

Those cases were not using ClientAttrib but they should :)
Rather use a OpenGL3.3 alternative anyways.

Fix collada exporting for Blender 2.8

Instead of exporting all the scene objects, I'm exporting the scene
layer objects instead.

Cleanup: redundant casts

Immediate Mode: removing unecessary comment on gpencil (false positive)

Image Draw: remove unused code since 2009

(removing false positive deprecated OpenGL calls)

Fix missing protection of `RNA_pointer_as_string()` against NULL pointers.

Odd that issue was never reached before? Looks like it hit in
datablock_idprops branch though...

Merge branch 'master' into blender2.8

Cycles: Tag shaders for update after the threading part is over

This avoids write access happening in non-atomic manner in
Shader::tag_update which modifies the global managers. Even
for 1 byte data types it's quite dangerous.

Depsgraph: Use atomic operation to tag the changed ID

Cycles: Fix uninitialized memory access when comparing curve mapping nodes

The issue is coming from the fact that float3 is actually 16 bytes aligned
data type and the "padding" was not initialized. This caused memcmp() to
access non-initialized memory.

install_deps: removed leftover compile_HDF5 command

It was a leftover from when Alembic with HDF5 was still officially
supported.

UV editor using new depsgraph for shadow uv