add userAgent to matching

Author: OrKoN

index.html

@@ -2116,6 +2116,11 @@ <h3>Processing capabilities</h3>
        used. The intent is that if this is not possible a new session
        will not be established.
 
+      <dt>"<code>userAgent</code>"
+      <dd><p>return <a>success</a> with data <a><code>null</code></a>.
+
+        <p class=note>Matching is not supported for this capability.
+
      <dt><strong>Otherwise</strong>
        <dd>
          <ul>