This functions checks and packages the fitting options for
survreg
survreg.control(maxiter=30, rel.tolerance=1e-09,
toler.chol=1e-10, iter.max, debug=0, outer.max=10)
maximum number of iterations
relative tolerance to declare convergence
Tolerance to declare Cholesky decomposition singular
same as maxiter
print debugging information
maximum number of outer iterations for choosing penalty parameters
A list with the same elements as the input