Don't immediately run links added to an Event/AsyncResult while it is running callbacks. Fixes #771.

Make the forewarn about 2.6 a permanant part of the readme that ends up on PyPi. It's not necessary to change whatsnew_1_1 in this branch, as RTD deploys from master. [skip ci]

Issue some warnings for patch_all with invalid parameters

Update socket docs to clarify their duplication of stdlib interface; tone down the warnings. [skip ci]

See changelog.rst for details.

Also skip the 'make' step on Windows if installing from an sdist (piggyback the Unix method of looking for Makefile/Makefile.ext). Ref #757.

Notes about cython on windows. XXX: Duplicated a couple places, intro.rst and README.rst, we should refactor.

- Kill older builds for the same PR automatically.
- Separate building and running tests.
  This lets us build and install a wheel up front so we don't have to do
  it again after running the tests (to distribute). This shaves 1+
  minute off each build for faster overall feedback.

Ignore the BlockingIOError name in server.py if running pyflakes on Py2; also sort the error lines by filename so they're easier to find. [skip ci]

Link socket and SSLSocket objects to their version appropriate
documentation on python.org.

Explicitly use the version-specific base socket class for SSLSocket.
This prevents the docs from listing the wrong base (because the docs are
built on Python 3 and so gevent.socket would be gevent._socket3, leading
the base of gevent._ssl2.SSLSocket to be gevent._socket3.socket).

Also, no need to 'from io import BlockingIOError' for Python 3. It
became a builtin in Python 3.3 which is the lowest version we support.

Move the Event/AsyncResult class-level _todo to a local, making classes cheaper to construct, and the _notify_links method and its interaction with _check_and_notify a bit less brain-teasing

http://bugs.python.org/issue13502

A race condition in Event that caused an improper return value if
greenlets were waiting while the event was set, but then immediately
cleared.

This was fixed in Python 3 but not (yet?) backported to Python 2.7, even
though the bug identifies that as a target.

Not only does this behaviour seem more obviously correct to me, it's
more future-proof: user share of Python 2 should be diminishing while
Python 3 share (with the correct behaviour) grows.