Various bugfixes and minor enhancements

* typo in .templates/nginx/nginx_static.inc
* better ACL comment in .templates/nginx/nginx_xport.inc
* missing dependency and wrong order in storage_gitbackup (MediaWiki, WordPress)
* wrong order in tools/build
* pointless warnings in tools/backup.d/xport_backup.sh
* new info file introduced: services/.ports

.templates/.ports

@@ -0,0 +1,7 @@
+# This is a human-readable summary of the port allocation.
+# To be maintained manually. You can use it as you like,
+# it doesn't matter for docker-skeleton automations.
+
+8100	ACME for SSL certificates
+
+8201

.templates/nginx/nginx_static.inc

@@ -6,5 +6,5 @@
         allow all;
         autoindex off;
         index index.html index.htm;
-        try_files $ri $uri/ =404;
+        try_files $uri $uri/ =404;
     }

.templates/nginx/nginx_xport.inc

@@ -2,10 +2,11 @@
     #
     # Export backups feature.
     # Needs
-    #   setfacl -m u:www-data:r    [...]/configs/xport_backup
-    #   setfacl -m u:www-data:rx   [...]/storage/backups
-    #   setfacl -m u:www-data:rx   [...]/storage/backups/export
-    #   setfacl -d -m u:www-data:r [...]/storage/backups/export
+    #   setfacl -m u:www-data:r    configs/xport_backup
+    #   chmod a-x                  configs/xport_backup
+    #   setfacl -m u:www-data:rx   storage/backups
+    #   setfacl -m u:www-data:rx   storage/backups/export
+    #   setfacl -d -m u:www-data:r storage/backups/export
     # ACLs.
     location /export {
         root $PAR_SERVICE/storage/backups;