Enhance compatibility with different transform types

[tbirdso]

itk::CommandExhaustiveLog's Python wrapping is limited to available wrappings for itk::Image, which by default is only wrapped for 2- and 3-dimensional images. This limits compatible transform types in Python to just those with with three or fewer parameters. One of three methods to enhance compatibility should be pursued:

• itk::Image could be wrapped for higher dimensions (but this could have a build time performance impact);
• a new itk::SpacedNdArray type could be added to dynamically set dimensionality at runtime (useful, but significant development effort would be necessary to rival the utility of itk::Image);
• itk::CommandExhaustiveLog could be extended to accept a list of up to three variable parameters as a subset of a longer list of transform parameters, the rest of which must be fixed during the exhaustive optimization.