Support Unicode and arbitrary callables. (Ticket #1019)
Support Unicode and arbitrary callables. (Ticket #1019)

rlayton pointed out that the metric fails when handed a Unicode
string rather than an ordinary string, and supplied a patch. I
(Anne Archibald) modified it somewhat so that the type checking
is done with isinstance(metric, basestring); I also modified the
function option to use callable(metric).

datamade/hcluster,datamade/hcluster,datamade/hcluster