RF: adapting image rollaxis to use Image
RF: adapting image rollaxis to use Image

Test for image.rollaxis used XYZImages throughout.  Construct Images
instead, relax constraints (we can now do operations on spatial axes)
and add tests for errors from non-diagonal affines.

alexis-roche/nipy,arokem/nipy,bthirion/nipy,nipy/nireg,arokem/nipy,alexis-roche/register,arokem/nipy,nipy/nipy-labs,nipy/nipy-labs,alexis-roche/nipy,bthirion/nipy,alexis-roche/nireg,alexis-roche/nipy,alexis-roche/nipy,alexis-roche/register,alexis-roche/register,nipy/nireg,alexis-roche/niseg,bthirion/nipy,arokem/nipy,bthirion/nipy,alexis-roche/nireg,alexis-roche/niseg