Volume visualisation, backgrounds, and much more
This release is by far the largest update to fsbrain so far. New features include:
- volume visualization (voxel-based, surface-generation from voxels, lightbox view, ...)
- major restructuring of the rendering code to make changes easier, based on color layers for meshes
- support for using backgrounds (e.g., mean curvature) when plotting surface data (yes, it's a color layer), see #6
- improved colorbar plotting: colorbars now go into a separate grid cell of the images
- support cortex_only parameter with more functions, fix #2
- major improvements to test infrastructure
- add new vignette for volume visualization, extend the surface vignette
and more.