Factor out HTTPAdapter.proxy_manager_for for #2048
update AUTHORS.rst
improve `proxy_manager_for` re-usability by subclass
allow pool_kwargs to be specified in init_poolmanager
compat: handle SyntaxError when importing simplejson

We officially support Python 2.6 to 3.3, but simplejson does not
support Python 3.1 or 3.2:

  https://github.com/simplejson/simplejson/issues/66

Importing simplejson on Python 3.2 results in a SyntaxError because
simplejson uses the u'...' syntax (the syntax was not supported in
Python 3.0 to 3.2).

Support for loading simplejson instead of the stdlib json module was
added by #710:

  https://github.com/kennethreitz/requests/pull/710

No mention was made of the lack of support for Python 3.2, but it was
mentioned that simplejson can be faster than the stdlib json module.
faq: mention that PyPy 2.2 works too

The FAQ says that PyPy 1.9 is supported. On my Debian Unstable, I can
install PyPy 2.2.1 and the tests work with that version too.
faq: add Python 3.4 to list of supported Python versions

No code changes were necessary for this.
test: restore Python 3.2 compatibility

The tests were broken because they used the u'...' Unicode literal
syntax which disappeared in Python 3.0 to 3.2.

We can work around this by conditionally defining a "u" function which
will produce a Unicode literal on Python 2.x. This is basically the
same approach as taken by the six library often used for writing
cross-version compatible code.
Document and initialise Response.request
Merge pull request #2069 from Lukasa/request

Document and initialise Response.request
Merge pull request #2065 from mgeisler/tox

Fix Python 3.2 compatibility in tests
Merge pull request #2064 from mgeisler/simplejson-syntax-error-import

compat: handle SyntaxError when importing simplejson
Merge pull request #2059 from jschneier/master

remove unused IteratorProxy
Check for basestring, not just str

Fixes #2071
Remove unnecessary check for builtin_str
Ensure that we open files in binary mode.
Merge pull request #2074 from Lukasa/filedoc

Ensure that we open files in binary mode in the docs.
Merge pull request #2072 from sigmavirus24/fix-urlencoded-bytes

Check for basestring, not just str
Allow copying of PreparedRequests without headers/cookies
Merge pull request #2078 from dgouldin/2077

Allow copying of PreparedRequests without headers/cookies