UP-4263 : Add RedirectRenderingPipelineTerminator

Add a `RedirectRenderingPipelineTerminator` `IPortalRenderingPipeline` implementation that simply redirects to a configured path, terminating the rendering pipeline.

See JIRA [UP-4263](https://issues.jasig.org/browse/UP-4263) and [context on MyUW's conditionally terminating the rendering pipeline in a redirect](http://apetro.ghost.io/pipelines-need-valves/).

## Logging

Logs at `TRACE` useful for development and troubleshooting.

```
TRACE o.j.p.r.BranchingRenderingPipeline - Branching to the true pipe [RedirectRenderingPipelineTerminator which redirects to /web .].
```

## Configuration example

Here's how MyUW is conditionally using this terminator.

```
<!-- This valve takes the place of the out of the box beginning of the pipeline, wrapping that ootb pipeline as one of the downstream branches, and redirecting as the other branch, depending upon a Predicate. -->
  <bean id="portalRenderingPipeline" class="org.jasig.portal.rendering.BranchingRenderingPipeline">
        <qualifier value="main" />
        <property name="predicate">
            ...
        </property>
        <property name="truePipe" ref="redirectToWeb" />
        <property name="falsePipe" ref="dynamicRenderingPipeline" />
    </bean>

    <bean id="redirectToWeb" class="org.jasig.portal.rendering.RedirectRenderingPipelineTerminator">
        <property name="redirectTo" value="${angular.landing.page}" />
    </bean>
```