initial commit

mostly a learning exercise, taking inspiration from packages such as
aiohttp, aiowsgi and picoweb - also, some snippets here proved useful to
get started:
http://www.drdobbs.com/open-source/the-new-asyncio-in-python-34-servers-pro/240168408

a previous attempt used a protocol class, but this seems simpler:
http://sandbox.tiddlyspace.com/_/27562117-e6eb-46fe-bce8-05827fa11bd2