Stop installing cffi on RTD. The compilation error *with* it is worse than the import error *without it*. (Compilation error is because only on PyPy do we move libev.h into the right place) [skip ci]

Actually make 'greenlet' a link. Fixes #386. Staged at http://python-gevent.readthedocs.org [skip ci]

Document the library updates, and call special attention to the changes in the c-ares configure script that can break on some CFLAGS/LDFLAGS configurations. [skip ci]

Add missing readable/writable methods to FileObjectPosix. Fixes at least help() on a monkey-patched Python 3

Updates for gevent.os.fork/waitpid, mostly documentation, but also make it possible to switch off the waitpid behaviour and access the 'basic' fork function.

- De-dup wait_read, etc, from socket2 and socket3 and call them out as gevent extensions.
- Doc create_connection on socket2 and socket3 since its a standard interface.
- Docstrings for gethostbyname, etc.

Debugging code for RTD and util/cythonpp.py. Also, don't force /usr/bin/python, use the environment python (better for virtual envs). [skip ci]

Add space to gcc command line for 32-bit builds.

Also convert all multi-line strings into lists. This keeps indentation specific and makes it easier to comment on individual items.

Fix a PEP8 error.

Fix some Windows failures and enable AppVeyor

 C:\Python27\python.exe -u test_hub_join_timeout.py
  Traceback (most recent call last):
    File "test_hub_join_timeout.py", line 44, in <module>
      result = gevent.wait(timeout=10)
    File "C:\Python27\lib\contextlib.py", line 24, in __exit__
      self.gen.next()
    File "test_hub_join_timeout.py", line 22, in expected_time
      assert expected - fuzzy <= elapsed <= expected + fuzzy, 'Expected: %r; elapsed: %r' % (expected, elapsed)
  AssertionError: Expected: 0.1; elapsed: 0.15600013732910156

it does not exist here. Instead, manually copy all build commands into appveyor.yml.

Note, ECHO without arguments prints "ECHO is off." on Windows, so it should not be used.

all scripts are from from https://github.com/ogrisel/python-appveyor-demo

see also https://packaging.python.org/en/latest/appveyor.html

Under Windows that command actually breaks stuff, since 'echo' without arguments prints 'ECHO is off.'.

libev\ev.c(1813) : error C2059: syntax error : 'type'

 Traceback (most recent call last):
    File "C:\projects\gevent\greentest\greentest.py", line 213, in wrapped
      return method(self, *args, **kwargs)
    File "C:\projects\gevent\greentest\greentest.py", line 202, in wrapped
      return method(self, *args, **kwargs)
    File "C:\projects\gevent\greentest\greentest.py", line 88, in wrapped
      return method(self, *args, **kwargs)
    File "C:\projects\gevent\greentest\test__server.py", line 267, in test_serve_forever
      self.assertConnectionRefused()
    File "C:\projects\gevent\greentest\test__server.py", line 114, in assertConnectionRefused
      conn = self.makefile()
    File "C:\projects\gevent\greentest\test__server.py", line 86, in makefile
      sock.connect((self.server.server_host, self.server.server_port))
    File "c:\projects\gevent\gevent\_socket3.py", line 261, in connect
      raise error(result, strerror(result))
    File "c:\projects\gevent\gevent\win32util.py", line 89, in formatError
      return self.winError(errorcode)[1]
  TypeError: 'OSError' object is not subscriptable