Merge branch 'blender2.8' into greasepencil-object

GP: Rename CTX and OB modes

Part of T59335.

Edit Curve: Add Normal size in overlay popover and change default range

Change default range to 0..2 to improve the slider behavior.

GP: Primitive: Revert adding new cursor and use nsew instead

Wireframe: Fix Object Viewport display "all edges" options not working

Curve Batch Cache: Add back support for shaded geometry

This changes a bit the batches data structure. Instead of using one
vbo per material we use one for all material and use index buffers for
selecting the correct triangles.

This is less optimized than before but has potential to become more
optimized by merging the wireframe data vbo into the shading one.

Also the index buffers are not strictly necessary and could be just
ranges inside the buffer. But this needs more adding things inside
GPUIndexBuf.

Curve Batch Cache: Rework Implementation to use new batch request

Shaded triangles are not yet implemented (request from gpumaterials).

This also changes the mechanism to draw curve normals to make it not
dependant on normal size display. This way different viewport can
reuse the same batch.

GPUBuffers: Fix uninitialized memory use causing undefined conditional jump

Displist: Reuse tesselated pos and nor for wireframes

This lower the memory usage and also fix a bug with metaballs normals/tris
winding being reversed.

DRW: Simplify text edit drawing

This is to simplify the curve batch cache.

GPUBatch: Add GPU_batch_clear to clear batches without freeing

Wireframe: Fix wireframe color in edit mode for surfaces

Curve Batch Cache: Add support for loose edges and curve/surf modifier

Fixes T58298 Nurbs circle and curve dont draw in objectmode
Fixes T58107 Modified curves/surfaces/fonts do not show their eval mesh

DRW Batch Cache: Fix hack being a bit too much hacky

Fix T59334: Crash initializing crazyspace on object with subsurf and displacement

GP: Primitive, fix move bug

UI: show frame rate in movie clip editor

Feature Request from Hjialti.

Attempt to sanitize node tree deletion

Make it explicit when freeing node tree which is owned by other
ID or when freeing node tree which is outside of a bmain.

Fix T59220: Deleting object causes blender 2.8 to crash

The issue was caused by a special code in node tree freeing function
which will free extra fields in the case when tree is not in bmain.
This is how old code was dealing with "nested" trees, but is now
making behavior different from other datablocks. This is exactly
what was confusing copy-on-write logic.

Ideally, ntreeFreeTree() need to behave same as all other datablocks,
ad freeing of data of nested trees should be up to the owner of the
tree (this way it's all explicit and does not depend on check of
some special flag.

Merge branch 'master' into blender2.8