• Fix an AttributeError from gevent.monkey.patch_builtins on
  Python 2 when the future_ library is also installed. Reported by
  Carlos Sanchez.
• PyPy: Fix a DistutilsModuleError or ImportError if the CFFI
  module backing gevent.core needs to be compiled when the hub is
  initialized (due to a missing or invalid __pycache__ directory).
  Now, the module will be automtically compiled when gevent is
  imported (this may produce compiler output on stdout). Reported in
  :issue:619 by Thinh Nguyen and :issue:631 by Andy Freeland, with
  contributions by Jay Oster and Matt Dupre.
• PyPy: Improve the performance of gevent.socket.socket:sendall
  with large inputs. bench_sendall.py_ now performs about as well on
  PyPy as it does on CPython, an improvement of 10x (from ~60MB/s to
  ~630MB/s). See this pypy bug_ for details.
• Fix a possible TypeError when calling gevent.socket.wait.
  Reported in #635 by lanstin.
• gevent.socket.socket:sendto properly respects the socket's
  blocking status (meaning it can raise EWOULDBLOCK now in cases it
  wouldn't have before). Reported in :pr:634 by Mike Kaplinskiy.
• Common lookup errors using the :mod:threaded resolver <gevent.resolver_thread> are no longer always printed to stderr
  since they are usually out of the programmer's control and caught
  explicitly. (Programming errors like TypeError are still
  printed.) Reported in :issue:617 by Jay Oster and Carlos Sanchez.
• PyPy: Fix a TypeError from gevent.idle(). Reported in
  :issue:639 by chilun2008.
• The imap_unordered methods of a pool support a maxsize
  parameter to limit the number of results buffered waiting for the
  consumer. Reported in :issue:638 by Sylvain Zimmer.
• The class gevent.queue.Queue now consistently orders multiple
  blocked waiting put and get callers in the order they
  arrived. Previously, due to an implementation quirk this was often
  roughly the case under CPython, but not under PyPy. Now they both
  behave the same.
• The class gevent.queue.Queue now supports the len() function.