Make geometric mean the default cluster determinants score.

    The cluster determinants score for a particular item is a
    combination of "within difference" and "between difference". This
    change calculates the aggregate score as the geometric mean of
    two. This makes the contribution of "within" and "between" parts
    more balanced. Other options are the difference or ratio of the
    scores (not enabled in the interface).
Allow selecting clustering method in cluster determinants.

    This is a bug fix. We displayed a "method" but the Makefile used
    'wm' for clustering regardless of the user's choice.
Allow "manual clustering" in cluster determinants.

    This adds an interface for clustering the data into two by hand
    for cluster determinants application. It is particularly useful
    when the automatic clustering methods cannot find the group or
    region of interest.