re owncloud latest

[matejc]

Since the rebase went a bit wrong I decided to help @aborsu (#10514) with that
by creating a new branch from master and cherry-picking his commits into, that how this pull request started.
@aborsu: do check the commits if I missed something when cherry-picking commits.

@aborsu: I have reviewed your code, looks solid, and specially... it works great, I will merge it as soon as travis-ci goes green and that you recheck the commits.
I have tried with multiple versions of owncloud and this is config for nixos-container:

{ config, lib, pkgs, ... }:
with lib;
{ boot.isContainer = true;
  networking.hostName = mkDefault "owncloud";
  networking.useDHCP = false;
  services = {
    httpd = {
      enable = true;
      adminAddr="some@email.beje";
      enablePHP = true;
      virtualHosts = [
        {
          extraSubservices = [
            {
              serviceType = "owncloud";
              dbUser = "owncloud";
              dbPassword = "SECRET";
              adminUser = "owncloud";
              adminPassword = "SECRET";
              package = pkgs.owncloud82;
            }
          ];
        }
      ];
    };
    postgresql.enable = true;
  };
}

I think there is no need for #10514 to exist anymore so it should be closed.

[mention-bot]

By analyzing the blame information on this pull request, we identified @pSub and @philandstuff to be potential reviewers

[aborsu]

@matejc
Thank you for your help.
You have all the commits, so if it is good for you it is good for me.
I'm still hoping to figure out why webdav is not working with the 8 version of owncloud, but since php is not even remotely my language of predilection I will be glad if anyone else wants to do it.

[matejc]

@aborsu, thank you.