T-test now works, and outputs a histogram as well as t-values and p-values.

fluents/workflow.py

@@ -241,8 +241,8 @@ class Options(dict):
     """
     def __init__(self, *args,**kw):
         dict.__init__(self, *args, **kw)
-        self['out_plots'] = None
-        self['out_data'] = None
+        self['out_plots'] = []
+        self['out_data'] = []
 	self['all_plots'] = []
 	self['all_data'] = []