Bessel function improvement 1 of ...: make faster thanks to avoiding unneeded gamma function calls. Still todo: fix bessely for integer order. Fix all bessel functions for large input.
Bessel function improvement 1 of ...: make faster thanks to avoiding unneeded gamma function calls. Still todo: fix bessely for integer order. Fix all bessel functions for large input.

lvandeve/jmat,lvandeve/jmat,lvandeve/jmat