Use a default port when comparing hosts to a connection pool

Added tests to verify and show expected behavior
Merge pull request #305 from nipunn1313/default_port

Use a default port when comparing hosts to a connection pool
CHANGES formatting.
_tunnel_host compatibility for Python 2.6.(0-2)

The _tunnel_host attribute was added in Python 2.6.3, so older Python 2.6's
failed when urllib3 would attempt to access the _tunnel_host attribute. This
change checks for the attribute's existence before accessing it. This fixes
Github issue #306.

Adds tests for this change.
python: how does it work
Merge pull request #307 from kevinburke/tunnel-no-tunnel

_tunnel_host compatibility for Python 2.6.(0-2)
_encode_body_methods isn't referenced anywhere
Merge pull request #308 from mattrobenolt/patch-1

_encode_body_methods isn't referenced anywhere
Disable TLS compression for Python 3.2+
Disable TLS compression in pyopenssl contrib module
Set preferred ciphersuites in pyopenssl contrib module
Move default SSL cipher list to root constant
Docs
Merge pull request #309 from dbrgn/disable_tls_compression

Disable TLS compression (CRIME)
CHANGES for #309
Account retries on ProxyError

Current implementation fails if it encounters a proxy error no
matter how many retries left.

Change the behaviour to try connecting until retry limit has reached
and then throw an appropriate exception: ProxyError or MaxRetryError.
Merge pull request #310 from novel/master

Account retries on ProxyError
Clean up CHANGES.
typo
Merge pull request #313 from kevinburke/typo

typo