Update to v0.15

From release notes:

    Big change, removing the brute-force method of Valdes et al.
    (PASP 107, 1119, 1995) for the more clever and robust technique
    of Tabur (PASJ 24, 189, 2007).  Tried to keep input/output/arguments
    the same, with very minor exceptions to input args.
Integrate v0.16

From news:

    Small but important fix: modified the control in "calc_trans()"
    inside atpmatch.c so that if one tentative match fails, the
    code does NOT immediately quit; now, it will go on to other
    possible matches.  More robust, but also can now report
    less-than-optimal matches.  May require more tuning to find the
    optimal match.
Merge tag 'v0.16'

Match v0.16 and Match v0.15