os: Implement few file and process functions.
os: Implement getpid() and waitpid().
multiprocessing: Add, with bare Process class implementation.
random: Add module placeholder.
os: Add fork()/pipe() test.
multiprocessing: Implement Pipe-alike.

Unfortunately, any Pipe used for parent/child child communication
needs to be registered with child Process. To get around that, would
need to keep global registry of Pipes, and that's bloat.
multiprocessing: Add dummy Pool implementation which doesn't really uses pool.
multiprocessing: Add trivial AsyncResult, not much async at all.
select: Add Epoll.close().
multiprocessing: Add AsyncResult.ready() with real async implementation.
multiprocessing: Add true async proof-test.
multiprocessing: Update metadata.
pickle: Add trivial pickle implementation using repr()/exec().
asyncio: Initial prototype implementation.
asyncio: Implement subclass implementing filedes watching interface.
asyncio: Recover eventloop's ability to work with callbacks.

Actually, coroutine support for call_soon() is a hack, in big asyncio coroutine
should be wrapped in Task object.
asyncio: Make run_forever() actually run forever.
asyncio: EpollEventLoop.wait(): support infinite wait.
asyncio: Support read/write syscalls, and route vals both ways between coros.
asyncio: Start adding asyncio stream interface.