Removed compress from accepted encodings.
Ensure that .raw() is present after unpickling.

Some people will assume that .raw() is present, and they shouldn't get
AttributeErrors when they make that assumption on a pickled Response.
However, @kennethreitz has asked that we not be too dependent on
urllib3. For that reason, set to None.
Split get_environ_proxies into two methods.

This makes it possible to get at the no_proxy logic separately.
Move auth rebuild to its own method.
Add method for rebuilding proxy configuration.

This includes auth.
Merge pull request #1949 from Lukasa/pickle

Pickled Responses should include a None value for the raw attribute
Merge pull request #1916 from schlamar/accept-encoding

Fix Accept-Encoding in default headers
Remove some extraneous comments to please KR.
Test stripping standard auth.
Fix #1960: A Response's history should be a list
Fix #1955: Do not use original request in redirect

The original request was never being properly overriden in resolve_redirects.
As such being having a POST request respond with a 303 would generate a GET
request. If the GET request encountered another redirect to something like a
307, then it would use the original request and generate another POST request.

There are two parts to this fix:

- The fix itself
- The test infrastructure to ensure it does not regress because HTTPBin is
  insufficient
Actually assign history
Style changes thanks to @sigmavirus24.
Merge pull request #1951 from Lukasa/proxyauth

Re-evaluate proxy authorization.
3.4
Merge remote-tracking branch 'origin/master'
Merge pull request #1963 from sigmavirus24/fix-redirect-methods

Fix #1955: Do not use original request in redirect
Merge pull request #1962 from sigmavirus24/fix-history-type

Fix #1960: A Response's history should be a list
The expected value changes for the proxies keyword

It used to be None but a recent PR changed that before my last one was merged
Merge pull request #1976 from kennethreitz/fix-redirect-test

The expected value changed for the proxies keyword