Add jacobian()... to SPGrid's geometry implementations
This avoids the deprecation warning of the default implementation.
The new methods return transposed views storing references
to the (cached) results of jacobianTransposed()
and
jacobianInverseTransposed()
.
Those views provide optimal implementations for right-multiplication to a FieldMatrix
in the sense that they rely on the (hopefully optimally implemented) mv()
method of the wrapped matrix.