calculated in one call.

numpy.dot). And a few tweaks elsewhere

between each of the three spaces (voxel, display, and world)

matrix), LightBoxPanel (not passing displayCtx to LightBoxCanvas),
fslview_parseargs (using imageList.bounds instead of displayCtx.bounds),
ImageList (didn't remove bounds-related code), ImageDisplay (attempting
to offset transformation matrices for affine, when only supposed to do
it for id/pixdim)

to use transform module instead of image.voxToWorld/worldToVox methods

coordinate systemss, with the ultimate aim of having the location panel
always reporting image world coordinates, regardless of the way in which
images are being displayed.