Surfa

- Added mesh self-intersection removal.
- Fixed ndarray and overlay casting.
- Fixed casting of ndarray to overlay.

- Added interpolation of image coordinates.
- Added segmentation recoding utilities.
- Added freesurfer-specific functions for surface label reading and label-lookups.
- Fixed propagation of label lookups.

- Added ray intersection, mesh knn, mesh smoothing, and spherical parameterization.
- Added auto-computing mesh properties.
- Fixed multi-frame overlay and slice writing and volume reshaping.
- Support for loading FS surface labels
- Support quadrangular FS mesh file loading.

- Added direct indexing support for overlays.
- Fixed bug when loading MGH files writen by ITK.

- Fixed NIFTI loading for newer nibabel versions.

- Fixed bug when loading MGH/MGZ files with no embedded FOV.
- Fixed broken `LabelLookup` initialization.