cacheable before creating the cache key.

This function does trivial things, but it's there to solve the problem
that the reduction neutral element getters are not allowed to store
dtypes (#80).

The function mangler demands that a function knows its type based on
its arguments. For the neutral element getters, this is impossible
because they take zero arguments. The simplest fix I can think of is
to change a call to neutral_element() to a call to make_tuple().

Currently, the tuple code doesn't work yet due to pickling issues.  I
think the root cause is somewhere in
__hackily_ensure_multi_argument_functions_are_scoped_private().

get included in dependency calculcations.

Add a save and reload test that uses base_storage.

array prefixes as they are aded to the set.

Closes #25 on gitlab
Depends on inducer/pytools!2 on gitlab

type. Now, the argument to a reduction can be either a scalar or a
tuple.

This reverts commit 7913e68a.

either a tuple, reduction, or a substitution invocation).

Also, rewrite the reduction mapping code to rely on recursive calls
map_tuple(). This cleans up a lot of reduction mapping code
substantially.

* Eliminates inames arguments to reduction functions (closes #32).
* Changes the argmax function to accept two arguments.

See also: #62

and __setstate__() doesn't run if the state is False.

Ensure that we always return a non-false state (another version bump
here).