Support for PROXY PROTOCOL

[deba12]

In my quest to place nginx infront of sstpd
i found one huge limitation: can't get user ip address due to proxy.
Please add support (with configuration switch)
for PROXY PROTOCOL
http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt
I am not sure which version nginx supports so please add both of them.

[sorz]

Support PROXY PROTOCOL under no-ssl mode should be easy.
But I don't how to implement it over TLS yet.

[deba12]

Implement it with no-ssl and mention it in the readme :)
It have to work with nginx.

[sorz]

BTW, nginx/1.11.8 use PP1.
PP2 was tested with haproxy.

[deba12]

Great to hear it :)
I will try it later today

Thanks