Djproxy

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- Fix X-Forwarded-For handling: The XFF header is now calculated
correctly and sent to the proxied resource. Previously, the XFF
header was being amended with the server's currenet IP address and it
was being sent to the requesting client during the response phase.
Now, the original request's header is amended with the client's IP
address before it is sent upstream.
- djproxy now sends the X-Forwarded-Host header to the proxied resource

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- Fix proxying of redirects. Previously, djproxy would follow redirects
and render the content of the final destination. This was wrong. It
now dutifully passes the redirect to the requester.
- Add ProxyPassReverse-like functionality via the reverse\_urls class
variable (which is now necessary because redirects are handled
correctly).
- Adds the ability to generate proxies and url patterns for them from a
configuration dict via the new ``generate_routes`` method.

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- Fix file uploads

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- Allow requests 2.1.0
- Allow Django 1.6 and fix tests to compensate for request factory
changes

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- Initial release