HTTP client improvements

• Full support for python 3.5

Core

• Added CI for python 3.5
• Added debug properties to all AsyncObject. The property returns the event loop
  debug mode flag

HttpClient

• Backward incompatible changes with API much closer to requests_ and far better support for streaming both uploads and downloads
• Added content attribute to HttpResponse, in line with requests_
• Ability to pass stream=True during a request, same API as python requests_
• Added the raw property to the Http Response, it can be used in conjunction with
  stream to stream http data. Similar API to requests_
• Renamed proxy_info to proxies, same API as python requests_
• You can now pass proxies dictionary during a request
• Stream uploads by passing a generator as data parameter
• Better websocket upgrade process
• Tidy up CONNECT request url (for tunneling)
• Added tests for proxyserver example using requests_

WSGI

• Both wsgi and http apps use the same pulsar.utils.httpurl.http_chunks
  function for transfer-encoding chunked
• render_error escapes the Exception message to prevent XSS_

Data Store

• Better pulsards_url function, default value form cfg.data_store
• key_value_save set to empty list by default (no persistence)

Examples

• Refactored proxy server example
• Updated django chat example so that warning are no longer issued

.. _requests: http://docs.python-requests.org/
.. _XSS: https://en.wikipedia.org/wiki/Cross-site_scripting
.. _async-await: https://www.python.org/dev/peps/pep-0492/#specification