STY: redundant args in stc.transform() and stc.transform_data()

How's this for a start?  It might be nice also to change all instances of <code>fun_args</code> to <code>func_args</code> (or vice versa), and <code>transform_fun</code> to <code>func</code> (or vice versa) for consistency.  But I guess that would change the API.  It wouldn't yet be such a big deal to modify the <code>stc.transform()</code> api, but I guess deeper changes would be required if we altered <code>stc.transform_data()</code>.