Blender Git Loki

Sculpt: Mask Filter and Dirty Mask generator

The mask filter operator modifies the whole paint mask. In includes multiple operations like smooth, grow or contrast accessible from a pie menu.
The dirty mask generator is similar to Dirty Vertex Colors, but it generates a paint mask. It can be used to mask cavities in the sculpt.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D5496