it does not seem possible that and event may need to be cancelled and DECREFed in __dealloc__

restore lazy creation of the Hub in get_hub() and the ability to replace greenlet.Hub with another class

proc.Proc.wait: simplify implementation and change signature a bit: exception instead of *throw_args

greentest/__init__.py: use greenlet and core accessible through gevent instead of importing them directly

multithreading is not supported by core.pyx yet

also, make core available as an attribute on gevent, so that the following works:
import gevent; gevent.core.something

- drop GreenFile (makefile() uses _fileobject), GreenPipe and GreenPipeSocket

- add greenlet.Waiter class (internal helper)

this avoids screwing up parent greenlet's switch()

socket: change order of arguments to ssl_listener to be in line with wrap_ssl() function; fix the tests

- all the functions from __init__.py were moved to gevent/greenlet.py; __init__ imports only some of them back
- gevent.timeout is now known as gevent.Timeout
- Hub now tries to recover after dispatch() failures (seen only(?) on epoll even though event_reinit() was called as necessary)
  This helps to pass test_socketserver.py all the time, not occasionally like before
- wsgi_test.py: move ssl tests to a separate class
- libevent version checking is gone as its done by gevent.core now

--HG--
rename : gevent/__init__.py => gevent/greenlet.py