Set global logging configuration from a Paste config.

Since gunicorn.app.pasterapp.{run, paste_server} are deprecated,
there is no way to configure the logging module from a Paste config
file.
Use pip instead of easy_install
Fix major issue with threaded worker keepalive

The keepalive queue management is fixed to not pop extra connections
incorrectly.

Close #816
Support UNIX sockets in gaiohttp worker
We need at least one argument for the WSGIApplication fix #815
support tornado 4.0

fix #771
fix django ex
doc: let django user know about the DJANGO_SETTINGS_MODULE env

improve the documentation to show the usage of the DJANGO_SETTINGS_MODULE
environment variable. related to #802.
example: edit paste example to allow the display of gunicorn logs
fix 19.1 changelogs
add missing people to THANKS
you probably know it but we are in 2014
Typo

s/suite/suit/
Display correct pid of already running instance
Fix `PyTest` class in setup.py.

It should be subclass of `setuptools.command.test`. Also, use it in
.travis.yml.