For non-network requests, like "localhost", it seems to be quite hard
to make gevent.ares to do the right (=compatible with stdlib) thing.

So we check if host does not have '.' and if that's the case,
we fallback to using threadpool.

This covers requests like "localhost", "ip6-localhost" and Python-specific
things, like "<broadcast>"

It's possible to disable this by passing use_threadpool=False to ResolverAres
or by settings resolver.pool = None.

For string ports (e.g. "http") resolver_ares/getaddrinfo previously only
consulted getservbyname(port, "tcp") or getservbyname(port, "udp"), but never both.

It seems that checking of both work (and creating result based on that) makes for
better compatibility with stock getaddrinfo, at least on linux.

it is not handled by test__monkey_patching.py

that way test runner does not fail on ubuntu where this tests are not available
a new test__monkey_patching.py is added which runs all stdlib tests

it can mask legitimate EINVAL cases, causing busy loop

this reopens issue #148

core: allow 'callback' property of a watcher to be set to None; del .callback is no longer supported

This fixes links execution order to be the same as they were added, fixing issue #143
The microbenchmarks show that it's not slower, in fact, a bit faster.

subprocess: add 'timeout' parameter to wait() in Windows case to avoid raising TypeError (timeout is ignored on Windows for now)

Fix issue #150: Do not wait for write event in gevent.fileobject.SocketAdapter.sendall() if everything was written already. Based on patch by Mark Hingston.

disable test_signal.SiginterruptTest.test_without_siginterrupt and test_siginterrupt_on because they rely on os.read raising EINTR which gevent.os.read does not do

otherwise it does not seem to work inside parallels on a mounted directory