COMP: Templated ITK Transform API change

The Transform class became templated such
that they now support both float and double
precision numbers natively.  This change
provides a nearly backwards compatible
typedef, but that typedef does not
propogate through the forward declaration
of the class.

// Forward decalaration for pointer
-class TransformBase;
+template< typename TScalar > class TransformBaseTemplate;
+typedef TransformBaseTemplate<double> TransformBase;