#2 Parameters are NOT copied

[Michael Peeters]

When taking a copy off a Vectorfunction<>, if the
user/programmer of the vectorfunction has not
explicitely taken care to redefine/copy all parameters,
they are no longer defined in the copy. SSA, for
example, barf on this, as well as any routines which
will use get_parameter("something") on a copy.
Obviously, the base class should take care of the
parameter copying.