schema: Add schema for disk <wwn>

* docs/formatdomain.html.in: Add document.
* docs/schemas/nodedev.rng: Move definition of "wwn" to ...
* docs/schemas/basictypes.rng: ...Here
* docs/schemas/domaincommon.rng: Add schema for disk <wwn>

docs/formatdomain.html.in

@@ -1582,6 +1582,12 @@
           like <code>&lt;serial&gt;WD-WMAP9A966149&lt;/serial&gt;</code>.
           <span class="since">Since 0.7.1</span>
       </dd>
+      <dt><code>wwn</code></dt>
+      <dd>If present, this element specifies the WWN (World Wide Name)
+        of a virtual hard disk or CD-ROM drive. It must be composed
+        of 16 hexadecimal digits.
+        <span class='since'>Since 0.10.1</span>
+      </dd>
       <dt><code>host</code></dt>
       <dd>The <code>host</code> element has two attributes "name" and "port",
         which specify the hostname and the port number. The meaning of this

docs/schemas/basictypes.rng

@@ -213,4 +213,10 @@
     </data>
   </define>
 
+  <define name='wwn'>
+    <data type='string'>
+      <param name='pattern'>[0-9a-fA-F]{16}</param>
+    </data>
+  </define>
+
 </grammar>

docs/schemas/domaincommon.rng

@@ -892,6 +892,11 @@
       <optional>
         <ref name="diskBlockIo"/>
       </optional>
+      <optional>
+        <element name="wwn">
+          <ref name="wwn"/>
+        </element>
+      </optional>
     </interleave>
   </define>
   <define name="snapshot">

docs/schemas/nodedev.rng

@@ -245,12 +245,6 @@
     </attribute>
   </define>
 
-  <define name='wwn'>
-    <data type='string'>
-      <param name='pattern'>[0-9a-fA-F]{16}</param>
-    </data>
-  </define>
-
   <define name='capsfchost'>
     <attribute name='type'>
       <value>fc_host</value>