ENH: use double instead of cloat wherever reasonable


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5069 42a5c34f-2066-0410-bec5-ba365beb4995
FIX: use more numerically-stable qform-to-matrix conversion from nifti1_io


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5070 42a5c34f-2066-0410-bec5-ba365beb4995
ADD: test inputs for three canonical orientations using qform, sform, and both


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5071 42a5c34f-2066-0410-bec5-ba365beb4995
ADD: tests and baselines for downsampling of NIFTI images with qform, sform, and both


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5072 42a5c34f-2066-0410-bec5-ba365beb4995