Log Message:
Updated py-cffi to 1.8.3.

v1.8.3
======

* When passing a ``void *`` argument to a function with a different
  pointer type, or vice-versa, the cast occurs automatically, like in C.
  The same occurs for initialization with ``ffi.new()`` and a few other
  places.  However, I thought that ``char *`` had the same
  property---but I was mistaken.  In C you get the usual warning if you
  try to give a ``char *`` to a ``char **`` argument, for example.
  Sorry about the confusion.  This has been fixed in CFFI by giving for
  now a warning, too.  It will turn into an error in a future version.