- Make the new granularity attribute private
- Simplify BaseEventLoop._run_once(): avoid math.ceil(), use simple arithmetic
  instead

The function is also moved to importlib.util.

BaseProactorEventLoop

Import them from submodules if you really need them.

http.server, imghdr, mailcap, mimetypes, xml.etree.

http.server, imghdr, mailcap, mimetypes, xml.etree.

Major changes:

- StreamReader.readexactly() now raises an IncompleteReadError if the
  end of stream is reached before we received enough bytes, instead of
  returning less bytes than requested.

- Unit tests use the main asyncio module instead of submodules like events

- _UnixWritePipeTransport now also supports character devices, as
  _UnixReadPipeTransport. Patch written by Jonathan Slenders.

- Export more symbols: BaseEventLoop, BaseProactorEventLoop,
  BaseSelectorEventLoop, Queue and Queue sublasses, Empty, Full

between the resolution of the BaseEventLoop.time() method and the resolution of
the selector. The granuarility is used in the scheduler to round time and
deadline.

EpollSelector.select() round again the timeout towards zero

select.epoll.poll() rounds again the timeout towards zero

towards zero

LZMACompressor.__init__ is left not converted.

a2b_qp() now accepts keyword arguments.
All "ascii" parameters is renamed to "data" for consistancy with a2b_qp().

also specified.

On Windows os.open() error message doesn't contain file name.