UP-4260 : Add ProfileFNamePredicate

Adds a `ProfileFNamePredicate` that returns `true` if a given request is in the context of the profile with the configured `fname`, and `false` otherwise.

See also JIRA [UP-4260](https://issues.jasig.org/browse/UP-4260) and context on [what MyUW is using this Predicate for](http://apetro.ghost.io/pipelines-need-valves/) in conditioning branching of the rendering pipeline.

Intended to be useful as a `Predicate` to plug into a `BranchingRenderingPipeline` to make that branching decision.

## Logging

Logs at `DEBUG` level details of how it is making its determination, useful for development and troubleshooting.

```
DEBUG o.j.p.r.p.ProfileFNamePredicate - User admin does have profile with matching fname bucky.
...
DEBUG o.j.p.r.p.ProfileFNamePredicate - Request for user guest presents profile fname default which does not match configured profile fname bucky.
```

## Configuration example

MyUW is using this predicate as part of the logic conditioning branching to a redirect out of the rendering pipeline.

```

  <bean id="portalRenderingPipeline" class="org.jasig.portal.rendering.BranchingRenderingPipeline">
        <qualifier value="main" />
        <property name="predicate">
            <!-- If using Bucky AND NOT focused on one portlet, redirect to /web. (true path)
                 otherwise proceed down regular dynamic rendering pipeline (false path). -->
            <bean class="com.google.common.base.Predicates" factory-method="and">
                <constructor-arg>
                    <list>
                        <bean class="org.jasig.portal.rendering.predicates.ProfileFNamePredicate">
                            <property name="profileFNameToMatch" value="bucky" />
                        </bean>
                        <ref bean="notFocusedOnOnePortletPredicate" />
                    </list>
                </constructor-arg>
            </bean>
        </property>
        <property name="truePipe" ref="redirectToWeb" />
        <property name="falsePipe" ref="dynamicRenderingPipeline" />
    </bean>
```