This most importantly fixes build issues related to C11 which is used in
for example OS X 10.11 ("El Capitan"):

    libev/ev.c:1029:42: error: '_Noreturn' keyword must precede function declarator
      ecb_inline void ecb_unreachable (void) ecb_noreturn;
                                             ^~~~~~~~~~~~

Make JoinableQueue.join consistent when items are passed to the constructor, extending #554; add a test for this.

Note that Python 2.5 support has been dropped. Add version and implementation classifiers to setup.py; make setup.py PyPy/Py3 friendly and not leak open files. [skip ci]

It was possible for IMap/IMapUnordered greenlets to exit without putting the final StopIteration. So, whoever was waiting on the results would have to wait forever (or until LoopExit if there's nothing else running in the program).

Original patch and test by @thinxer (close #424).

Fix #311: same issue.

from gevent013 branch

Do not mention gevent.six in changelog, it's not part of public interface and might be removed in the future