Documentation for pool and semaphore. Add return types for some Cython semaphore functions in hopes of better code.

Use the return value of the function, don't shortcut through the current thread. sometimes under py3 the current thread id isn't set, and the release() methods we're trying to patch around use get_ident() anyway. Fixes #615. Really, not just the test cases.

Cleanup logging locks that were created before monkey patching thread. Also, fix monkey patching of threading.RLock under Python 3.

Provide better, pro-active error messages if a non-callable is asked to be spawned as a greenlet. Fixes #119.

Add a monkey-patch for __import__ that properly locks multiple greenlets. Apply it automatically under python 2 (not needed on Py3). Fixes #108.

Implement FileObjectPosix on top of `io` in Python 2.

Documentation for hub.reinit. Avoid printing an error on shutdown if gevent.threading is just imported but not monkey patched.

The PyPy patch for the main thread is applicable anywhere that the stdlib threading module was imported before monkey patching. Fixes #153

Make chunked encoding handling of untrusted client data more robust and safer in gevent.pywsgi.

Make chunked encoding handling of untrusted client data more robust and safer in gevent.pywsgi. Fixes #229.