Per the docs, mktime expects a time struct in local time, not UTC:
https://docs.python.org/2/library/time.html#time.mktime

This mismatch was causing TestDate.test_fromtimestamp in
test_datetime.py to fail on some systems.

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.