Fix: logger_class can be undefined.
Merge pull request #741 from ifduyue/logger_class_bug

Fix: logger_class can be undefined.
Fix mixed up worker signal handling

Commit 81241907ffcf94517ffa14b8427205906b61b540 changed the signal
handling by switching the roles of `TERM` and `QUIT` for the arbiter
so that `TERM` is graceful and `QUIT` is not.

At the time, workers performed graceful shutdown on `QUIT` and quick
shutdown on `TERM` and `INT`. This behavior was also changed so that
`QUIT` (and `INT`) cause a quick shutdown and `TERM` is graceful.

However, the documentation incorrectly reversed the roles of the worker
signals and the arbiter was not updated to use the correct signals.

This commit fixes the documentation and the arbiter signals.
Move setting of environmental variables before preload_app start.

Move setting of env vars from Arbiter.start to Arbiter.setup so that they are available during application start up when 'preload_app' is used.

Closes #735
Merge pull request #740 from tshlabs/735-envvars-preload

Move setting of environmental variables (configured via the raw_env sett...
Remove unused imports
Merge pull request #746 from ifduyue/remove_unused_imports

Remove unused imports
Stop all servers
Merge pull request #747 from wooparadog/stop-all-servers

Stop all servers
Merge pull request #745 from tilgovi/worker-signals-mixup

Fix mixed up worker signal handling
Remove __future__.with_statement imports.

Gunicorn requires Python 2.6 or newer now:

http://docs.gunicorn.org/en/latest/install.html#requirements
Remove the redundant if clause in gunicorn/workers/workertmp.py.
Add Python 3.4 to classifiers.

I tested Gunicorn with the following command on Pytohn 3.4.0:

    $ python3.4 -m venv venv34
    $ . venv34/bin/activate
    $ pip install -e .
    $ pip install -r requirements_dev.txt
    $ py.test tests/
Also, enable Python 3.4 on Travis CI.

(The "--use-mirrors" option was deprecated, so I removed it.)
Merge pull request #751 from berkerpeksag/classifiers-python3.4

Add Python 3.4 to classifiers.
Merge pull request #749 from berkerpeksag/remove-with_statement

Remove __future__.with_statement imports.
Merge pull request #750 from berkerpeksag/startswith-idiom

Remove the redundant if clause in gunicorn/workers/workertmp.py.
Cleanup Makefile.

- The "--no-site-packages" option is default now
- "pip install -e" is basically equivalent to "python setup.py develop"
- Delete also dist/ and MANIFEST
- Delete all *.py[co] files (and __pycache__ directories on Python 3)
Update installation docs to mention about pip.

Other changes:

- Minor markup and style changes
- Use https in URLs
- Remove the "python setup.py develop" part from the
  documentation. It's useful for development.
Merge pull request #752 from berkerpeksag/cleanup-makefile

Cleanup Makefile.