treewide: add bool type to enable options, or make use of mkEnableOption

Add missing type information to manually specified enable options or replace them by mkEnableOption where appropriate.

nixos/modules/services/network-filesystems/netatalk.nix

@@ -43,10 +43,7 @@ in
   options = {
     services.netatalk = {
 
-      enable = mkOption {
-          default = false;
-          description = "Whether to enable the Netatalk AFP fileserver.";
-        };
+      enable = mkEnableOption "the Netatalk AFP fileserver";
 
       port = mkOption {
         default = 548;
@@ -65,6 +62,7 @@ in
 
       homes = {
         enable = mkOption {
+          type = types.bool;
           default = false;
           description = "Enable sharing of the UNIX server user home directories.";
         };

nixos/modules/services/network-filesystems/rsyncd.nix

@@ -29,10 +29,7 @@ in
   options = {
     services.rsyncd = {
 
-      enable = mkOption {
-        default = false;
-        description = "Whether to enable the rsync daemon.";
-      };
+      enable = mkEnableOption "the rsync daemon";
 
       motd = mkOption {
         type = types.str;

nixos/modules/services/network-filesystems/xtreemfs.nix

@@ -100,11 +100,13 @@ in
 
       dir = {
         enable = mkOption {
+          type = types.bool;
           default = true;
           description = ''
             Whether to enable XtreemFS DIR service.
           '';
         };
+
         uuid = mkOption {
           example = "eacb6bab-f444-4ebf-a06a-3f72d7465e40";
           description = ''
@@ -218,11 +220,13 @@ in
 
       mrc = {
         enable = mkOption {
+          type = types.bool;
           default = true;
           description = ''
             Whether to enable XtreemFS MRC service.
           '';
         };
+
         uuid = mkOption {
           example = "eacb6bab-f444-4ebf-a06a-3f72d7465e41";
           description = ''
@@ -354,11 +358,13 @@ in
 
       osd = {
         enable = mkOption {
+          type = types.bool;
           default = true;
           description = ''
             Whether to enable XtreemFS OSD service.
           '';
         };
+
         uuid = mkOption {
           example = "eacb6bab-f444-4ebf-a06a-3f72d7465e42";
           description = ''

nixos/modules/services/network-filesystems/yandex-disk.nix

@@ -21,6 +21,7 @@ in
     services.yandex-disk = {
 
       enable = mkOption {
+        type = types.bool;
         default = false;
         description = "
           Whether to enable Yandex-disk client. See https://disk.yandex.ru/