Add "portletMode" parameter to PortletActionRedirectResult

Add "portletMode" parameter to PortletActionRedirectResult so one can switch to a different portlet mode in when dispatching to the render phase.

Example:

<action name="index" class="com.myportlet.UpdateNameAction">
<result type="redirectAction">
<param name="actionName">index</param>
<param name="portletMode">view</param>
</result>
<result name="input">/WEB-INF/jsp/edit/index.jsp</result>
</action>