upgrade pypy tests to 2.7.8

Fix #497.

upgrade libev to 4.19

update known_failures.py w.r.t PyPy upgrade

import socket on windows

https://bugs.pypy.org/issue1743 is fixed now, but other failures appeared.

Should fix #459. See https://github.com/gevent/gevent/issues/459#issuecomment-49506870

Thanks to @snaury.

This reverts commit 12e4fb18.

cythonpp.py: fix breakage on newer cython versions

Thanks to @zhangchunlin and @mvalkon.

Fix #483. Close #489.

Remove extra backtick

Markdown typo correction

peek() should return the same element that get() returns, which
is not currently the case.

Add regression test for queue peek().

Fix broken link in the Introduction doc

- bugfix for error: ISO C90 forbids mixed declarations and code in libev...

made gevent.corecffi buildable under 32 bit systems

- mark test__os.py as flaky on python-dbg
- remove test_queue.py and test__threading_vs_settrace.py from FAILING

To prevent this:

======================================================================
FAIL: test_terminate (__main__.TestPool10)
----------------------------------------------------------------------

Traceback (most recent call last):

File "test__threadpool.py", line 176, in test_terminate

assert kill.elapsed < 0.5, kill.elapsed

AssertionError: 0.564028263092041

too slow