Adapt the relaxNG files to new gui changes

This was SVN commit r15382.

binaries/data/mods/public/gui/gui.rnc

@@ -4,7 +4,7 @@ namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"
 #   and use a converter tool like trang to generate the Relax NG XML (.rng) file
 ##
 
-start = objects | setup | sprites | styles
+start = object | objects | setup | sprites | styles
 
 ##
 # Types #
@@ -149,7 +149,8 @@ def =
   }
 \include =
   element include {
-    attribute file { text }
+	attribute file { text }|
+    attribute directory { text }
 }
 item =
   element item {

binaries/data/mods/public/gui/gui.rng

@@ -8,6 +8,7 @@
     -->
     <a:documentation/>
     <choice>
+      <ref name="object"/>
       <ref name="objects"/>
       <ref name="setup"/>
       <ref name="sprites"/>
@@ -484,7 +485,10 @@
   </define>
   <define name="include">
     <element name="include">
+      <choice>
         <attribute name="file"/>
+        <attribute name="directory"/>
+      </choice>
     </element>
   </define>
   <define name="item">