Log Message:
Update to 0.58

Upstream changes:
0.58 2016-05-21

    [API Changes]

    - prev_prime($n) where $n <= 2 now returns undef instead of 0.  This
      may enable catching range errors, and is technically more correct.

    - nth_prime(0) now returns undef instead of 0.  This should help catch
      cases where the base wasn't understood.  The change is similar for
      all the nth_* functions (e.g. nth_twin_prime).

    - sumdigits(n,base) will interpret n as a number in the given base,
      rather than the Pari/GP method of converting decimal n to that base
      then summing.  This allows sumdigits to easily sum hex strings.
      The old behavior is easily done with vecsum(todigits(n, base)).

    - binary() was not intended to be released (todigits and todigitstring
      are supersets), but the documentation got left in.  Remove docs.

    [ADDED]

    - addmod(a, b, n)                     a + b mod n
    - mulmod(a, b, n)                     a * b mod n
    - divmod(a, b, n)                     a / b mod n
    - powmod(a, b, n)                     a ^ b mod n
    - sqrtmod(a, n)                       modular square root
    - is_euler_pseudoprime(n,a[...])      Euler test to given bases
    - is_primitive_root(r, n)             is r a primitive root mod n
    - is_quasi_carmichael(n)              is n a Quasi-Carmichael number
    - hclassno(n)                         Hurwitz class number H(n) * 12
    - sieve_range(n, width, depth)        sieve to given depth, return offsets

    [FUNCTIONALITY AND PERFORMANCE]

    - Fixed incorrect table entries for 2^16th Ramanujan prime count and
      nth_ramanujan_prime(23744).

    - foroddcomposites with certain arguments would start with 10 instead of 9.

    - lucasu and lucasv should return bigint types.

    - vecsum will handle 128-bit sums internally (performance increase).

    - Speedup is_carmichael.

    - Speedup znprimroot, 10% for small inputs, 10x for large composites.

    - Speedup znlog ~2x.  It is now Rho racing an interleaved BSGS.

    - Change AKS to Bernstein 2003 theorem 4.1.
      5-20x faster than Bornemann, 20000+x faster than V6.

    - sum_primes now uses tables for native sizes (performance increase).

    - ramanujan_tau uses Cohen's hclassno method instead of the sigma
      calculation.  This is 3-4x faster than the GMP code for inputs > 300k,
      and much faster than the older PP code.

    - fromdigits much faster for large base-10 arrays.  Timing is better than
      split plus join when output is a bigint.