Expose "proxy_connect_timeout" for Nginx when it connects to the backends.

Also, correct CHANGELOG.md for two previous changes (minor update).

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Move `proxy_connect_timeout' to Nginx attributes.

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Merge pull request #615 from opscode/kw/proxy_connect_timeout

Expose "proxy_connect_timeout" for Nginx when it connects to the backend...