[PATCH] Check number of parameters when reading function from archive.

[PATCH] Check number of parameters when reading function from archive.

Functions where looked up by their function name in archives. However,
some functions have overloads for different numbers of parameters
('zeta', 'G', 'psi'). Reading archives could pick the wrong overload.

Fixed by requiring that the actual number of function parameters in the
archive node must equal the function's declared number of parameters.

Thanks to Feng Feng for reporting this problem.