High level HTTP connection class

[keithduncan]

This should be a member of the AFNetworkURLConnection class cluster for http[s] scheme URLs and implement these behaviours

• Authentication
  • [ ] Basic http://tools.ietf.org/html/rfc2617#section-2
  • [ ] Digest http://tools.ietf.org/html/rfc2617#section-3
  • [ ] OAuth 1.0 https://tools.ietf.org/html/rfc5849
  • [ ] TLS
• Redirection
  • [ ] 301 http://tools.ietf.org/html/rfc2616#section-10.3.2
  • [ ] 302 http://tools.ietf.org/html/rfc2616#section-10.3.3
  • [ ] 303 http://tools.ietf.org/html/rfc2616#section-10.3.4
  • [ ] 307 http://tools.ietf.org/html/rfc2616#section-10.3.8
• Caching
  • [ ] Caching
• Expectation Failed
  • [ ] Removing a 100-continue token from the Expect header
• Upgrade Required
  • [ ] Support in-band upgrade to TLS http://tools.ietf.org/html/rfc2817
• Pipelining
  • [ ] Pipelining