nonlinear module. Expand x5 module to handle non-linear. Rename x5 functions
to be more generic.

intent code to be changed. Nifti class emits new "header" notifier topic
when intent changes.

read/write routines

be useful outside of the Nifti class (for testing, at least)

fsl, and world coordinate systems. New getAffine method allows you to get an
affine between any of the coordinate systems

dimensions

a file name. Bitmap.asImage passes dataSource through to Image.__init__

are still shaped (w, h, c), where c == 1

pass one at a time

copying data if possible, and avoid copydeprecation warnings.

arrays (e.g. RGB data)

Works around older numpy versions

these return 3D images with the binary or probabilistic mask
in a new image.Image with the name set to the label name
and the same NIFTI header as the atlas