Build as Dynamic module support; sockets; fixes

[cryptofuture]

What pull request includes.

1. Build as Dynamic module support for ngx_postgres (very old checks removed also)
2. Less raw nginx 1.11.6+ support. More accurate fix.
3. Backport of pull #24 request. Thats sockets support.
   I personally maintain nginx-hda-bundle, and I want to switch it to your repository.
   Main ngx_postgres repository ignores pull request for years, and current guy who "moderate it" is very stubborn.
   Basically, I also want to make your readme less scary, if its possible.

[Inviz]

Hello Friend. I'm sorry for a bit dated answer. I took a hiatus from this project while looking for job, but I'm thinking of getting back again soon. Thank you for understanding.

First thing first, I think dynamic loaded modules is a great idea, I never had enough time to port my modules to that stuff. So have my thanks for poking me, I'm in for it.

I appreciate you considering my fork more active-ish, however some peeps may object to features I added to ngx_postgres, but there's a decent bunch of good ones too. I tried to avoid contamination of things, so the module would be suitable for general public. So I think what you want is possible, I could clean up README by now, as I think there's nothing too untested or not ready for production. No reason that I know of to warn people about stuff.

Sockets are a great addition, thank you.

[Inviz]

I attempted to make readme less scary and mentioned your additions of socket/dynamic module loading.

If you will have any ideas about collaboration or something feel free to drop me an email at invizko@gmail.com .

Your help is very well appreciated, have a wonderful time.

[Inviz]

I also added you as a collaborator just in case.