dictNE was checking v.isInstance(DictType) instead of checking w. This
causes a variety of undefined behavior including segfault, invalid mutex
state, etc.

Addresses https://github.com/google/grumpy/issues/56

In CPython the function form is twice as slow.

This eliminates an extra allocation for the backing array by storing it in the
memory directly following the tuple itself.

This patch adds minimal support for complex numbers.
Complex literals can be parsed and a very minimal
complex number type has been added to the runtime.
While minimal, the basic pieces are fleshed out enough
that producing follow-on patches to incrementally
develop `complex` should be easy.

Method covered by new benchmarks:
* Dict.GetItem
* Dict.IterItems
* Dict.IterKeys
* Dict.IterValues
* NewInt - Fixed so that references aren't elided anymore.
* NewStr

As specified here:

* https://docs.python.org/2/library/stdtypes.html#sequence-types-str-unicode-list-tuple-bytearray-buffer-xrange

This commit only uses the sequence count method for `list.count`,
but it can easily be applied to other sequence types in follow-on
commits.