Blender Git Loki

Merge branch 'master' into soc-2021-porting-modifiers-to-nodes-merge-by-distance

# Conflicts:
# release/scripts/startup/nodeitems_builtins.py
# source/blender/blenkernel/BKE_node.h
# source/blender/blenkernel/intern/node.cc
# source/blender/makesrna/RNA_enum_types.h
# source/blender/makesrna/intern/rna_nodetree.c
# source/blender/modifiers/intern/MOD_weld.c
# source/blender/nodes/NOD_geometry.h
# source/blender/nodes/NOD_static_types.h