Move all of NixOS to nixos/ in preparation of the repository merge

nixos/modules/services/misc/svnserve.nix

@@ -0,0 +1,46 @@
+# SVN server
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+
+  cfg = config.services.svnserve;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.svnserve = {
+
+      enable = mkOption {
+        default = false;
+        description = "Whether to enable svnserve to serve Subversion repositories through the SVN protocol.";
+      };
+
+      svnBaseDir = mkOption {
+        default = "/repos";
+	description = "Base directory from which Subversion repositories are accessed.";
+      };
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+    jobs.svnserve = {
+      startOn = "started network-interfaces";
+      stopOn = "stopping network-interfaces";
+
+      preStart = "mkdir -p ${cfg.svnBaseDir}";
+
+      exec = "${pkgs.subversion}/bin/svnserve -r ${cfg.svnBaseDir} -d --foreground --pid-file=/var/run/svnserve.pid";
+    };
+  };
+}