Blender Git Loki

Fix build on windows after ccg changes

Merge branch 'blender2.8' of https://git.blender.org/blender into blender2.8

Multires: Allow changing sculpt level without loosing data

As the comment states, this is not really great solution, but
is good enough for now. Proper solution needs some more work,
and maybe reconsideration of what is stored where.

CustomData: Allow copying content of a single layer

Fix T56912: bpy.data.masks.new() crashed

I think there are two possible ways to fix that.
1. Make the name a required parameter.
2. Provide a default value.

I choosed option 1 in this fix to be consistent with other .new functions.

Also I think `RNA_def_string` instead of `RNA_def_string_file_path` should be used here. Looks like a copy-paste error.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D3728

Cleanup: indentation

Multires: Make code more ready for mesh uised by multiple objects

Probably more work is needed, but is good starting point.

Cleanup: Variable name in mesh runtime

Matches type better, avoiding possible confusion.

Multires: Pass total level instead of modifier data

This is the only thing which needs to be done to perform propoer
reshape. Makes it easier to re-use code from other places.

Multires: Pass mesh instead of object

There is nothing we need from object in this case.

Gizmo: dial support for a click setting a value

Useful for click w/o drag to spin a full revolution.

Gizmo: reset dial value on cancel

Gizmo: support spin tool normal flipping

Use the 2x spin tool has 2x handles to control normal direction,
dragging either handle backwards now reverses normals.

Previously it was common for the spin result to have normals
flipped the wrong way.

Missing from last commit

Merge branch 'master' into blender2.8

BMesh: option to flip normals for extrude/spin

Merge branch 'master' into blender2.8

Cleanup: style

GP: Move MIrror modifier to Generate column

GP: Move Unlock Color to Adjustments panel

This option is not used all the time and can be moved to additional panel