Add package pshs-0.2.5

Announcement blog post:
http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/licenses/

pkgs/servers/http/pshs/default.nix

···
+{ stdenv, fetchurl, pkgconfig, libevent, file, qrencode }:
+
+let
+  version = "0.2.5";
+in stdenv.mkDerivation {
+  name = "pshs-${version}";
+
+  src = fetchurl {
+    url = "https://www.bitbucket.org/mgorny/pshs/downloads/pshs-${version}.tar.bz2";
+    sha256 = "1lbybww9b74a9ssrii15w6qby0d66j367kara7kmfhakpv8jsvyh";
+  };
+
+  buildInputs = [ pkgconfig libevent file qrencode ];
+
+  # TODO: enable ssl once dependencies
+  # (libssl libcrypto libevent >= 2.1 libevent_openssl) can be met
+  configureFlags = "--disable-ssl";
+
+  meta = {
+    description = "Pretty small HTTP server - a command-line tool to share files";
+    homepage = "https://bitbucket.org/mgorny/pshs/";
+    license = stdenv.lib.licenses.bsd3;
+    maintainers = [ stdenv.lib.maintainers.eduarrrd ];
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   postfix = postfix211;
 
+  pshs = callPackage ../servers/http/pshs { };
+
   pulseaudio = callPackage ../servers/pulseaudio {
     gconf = gnome.GConf;
     # The following are disabled in the default build, because if this