adolc.hh: define `Dune::Simd::IsStandard` for ADOLC's adouble
This is required for dune-common to work correctly. Without this
change tests in dune-elasticity that use adolclocalenergy.hh failed to
build as they used an incomplete type
Dune::Simd::Overloads::IndexType<adouble, void>
somewhere in dune-common's fmatrix.hh.
Also define IsNumber while at it. dune-common's gmpfield.hh does
the same.