Blender Git Loki

Merge branch 'master' into soc-2020-testing-frameworks

Removed cloth Pressure and Self Collision tests

added warning and disable self collisions for non closed meshes

Cleanup: move break statements into case body, or remove if follwing a return.

Cleanup: spelling

Cleanup: use doxy sections for fcurve.c

Cleanup: remove f-string use

fixed bug when switching mesh types

Rename some classes at the suggestion of reviewers.

Mesh -> IMesh; MArena -> IMeshArena
Remove type abbreviations Vertp and Facep.

Cleanup: remove duplicated code from previously unnoticed merge conflict

`BKE_animdata_blend_expand` is called in `expand_id` already.

Refactor: move animdata code from blenloader to blenkernel

Refactor: move nla code from blenloader to blenkernel

GPencil: Report operators that are not implemented

LineArt: "Intersection Only" flag for objects/collections

Cleanup: remove LodLevel

This was part of the game engine and is not used anymore.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D8666

Refactor: move fcurve/fmodifier code from blenloader to blenkernel

This is part of T76372.

Cleanup: use LISTBASE_FOREACH in readfile.c

GPencil: Remove unessesary curve edit mode test

GPUShader: Fix linking working even if one shader compilation failed

Linking without valid shaders works on some drivers. Avoid this case by
forcing linking step to return false.

GPencil: Draw transform gizmo curve edit