Update Quamash to work with Python 3.4 asyncio

Hi Mark

I have re-written Quamash to make it work with Python 3.4 asyncio and PyQt 5/PySide. Note that I have only tested with PyQt 5 on Windows so far, and what I have tested is reflected in the automatic tests I've written (in the tests/ directory). Not sure how easy it would be to support older versions of Python. This was my first exposure to Python async, except Twisted.