documented cc.py and cutils.py

gof/cutils.py

@@ -6,6 +6,9 @@ except ImportError:
 
     from scipy import weave
 
+    # The following function takes a PyCObject instance that contains
+    # a void*->int function in its VoidPtr field. It then calls that
+    # function on the object's Desc field and returns the int result.
     single_runner = """
         if (!PyCObject_Check(py_cthunk)) {
             PyErr_SetString(PyExc_ValueError,