Add the DefaultServlet in web.xml to allow HTTP PUT and DELETE

This is required allow deleting uploads (where the JavaScript executes a
HTTP DELETE).

src/main/webapp/WEB-INF/web.xml

@@ -33,6 +33,31 @@
 		<url-pattern>/error500</url-pattern>
 	</servlet-mapping>
 
+	<servlet>
+		<servlet-name>default</servlet-name>
+		<servlet-class>
+			org.apache.catalina.servlets.DefaultServlet
+		</servlet-class>
+		<init-param>
+			<param-name>debug</param-name>
+			<param-value>0</param-value>
+		</init-param>
+		<init-param>
+			<param-name>listings</param-name>
+			<param-value>false</param-value>
+		</init-param>
+		<init-param>
+			<!-- Allow HTTP PUT and DELETE (for attachments) -->
+			<param-name>readonly</param-name>
+			<param-value>false</param-value>
+		</init-param>
+		<load-on-startup>1</load-on-startup>
+	</servlet>
+	<servlet-mapping>
+		<servlet-name>default</servlet-name>
+		<url-pattern>/</url-pattern>
+	</servlet-mapping>
+
 	<error-page>
 		<error-code>500</error-code>
 		<location>/error500</location>