Overwrite voxel order when anatomy is provided.
Set voxel_order to LPS if affine is invalid (all zeros).
Overwrite voxel_order by guessing the affine of the anatomy if provided.
Change version number
Merge pull request #25 from MarcCote/set_trk_voxel_order

Overwrite voxel_order by guessing the affine of the anatomy if provided.