Allows headers dict to contain iterables

HTTP allows for a header to be sent multiple times with different values
(provided they could otherwise be combined into one header with an ;
character).  This is the current preferred method for setting cookies
with Set-Cookie.

Added support for provided header values as iterables, for which each
item in the iterable will be in it's own header line.  Order is
preserved, as the HTTP spec requires.

Added documentation for feature.

Ref: http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2
add reconnecting WebSocket client
Issue #275: Fix asyncio for Python 3.4.2

Don't use asyncio submodule (asyncio.tasks), iscoroutine() is directly
exposed in the asyncio namespace. In Python 3.4.2, iscoroutine() was
moved from asyncio.tasks to asyncio.coroutines.
Use explicitly trollius

The code uses "yield" which is only supported by trollius. asyncio
raises a RuntimeError.

The asyncio module has no Return() function.
Move "import trollius as asyncio" at the top

The asyncio symbol is needed before the import, so move the import at
the top.
Merge pull request #278 from haypo/master

Issue #275: Fix asyncio for Python 3.4.2
Merge pull request #279 from haypo/trollius10

Fixes to support Trollius 1.0 with Python 2.7 and 3.3
Merge pull request #273 from Hooksie/iter-headers

Allows headers dict to contain iterables
update AutobahnJS
fix docstring
add Windows minimal install hints
fix one more wrong asyncio import
add parameters to Flash policy factory
cancel WebSocket opening handshake timeout also on clients
consistent whichspace
fixes #276
bump version
 Fix handling of receive of close frame in corner case - fixes #283
whitespace cosmetics
Fix format() use for Python 2.6 - fixes #285