SPR-7641 - Added Principal to listing of supported method parameter types.

spring-framework-reference/src/mvc.xml

@@ -1025,6 +1025,11 @@ public class RelativePathUriTemplateController {
               exposed by the Servlet API.</para>
             </listitem>
 
+            <listitem>
+              <para><interfacename>java.security.Principal</interfacename>
+              containing the currently authenticated user.</para>
+            </listitem>
+
             <listitem>
               <para><classname>@PathVariable</classname> annotated parameters
               for access to URI template variables. See <xref