REDUCE Code

and to avoid division by zero errors in some boundary cases. Also added code for the symmetric
integral of the 2nd kind RG and recoded RJ to avoid repeated calculation of RC at each stage of
the iteration as suggested by Carlson & FitzSimmons (2000).

Also following the same paper, recode the functions ellint_1st, ellint_2nd and ellint_3rd to avoid
some errors which could occasionally occur in examples where the integrand is the square root of two
pairs of complex conjugate factors. The results should now be correct whenever the integrand is real
and there no branch points interior to the range of integration.

doc/manual/ellipfn.tex and manual.pdf: Addition to the manual to document the changes to efnumeric.