Governator bootstrap based servlet subproject

Integrate GuiceServletContextListener into Governator's bootstrap mechanism.  This integration will drive LifecycleManager start()/close() from the ServletContext events.  In addition it provides a mechanism to hook into the ServletContextListener via a custom ServletContextListener that is created within the context of Guice and can therefore inject dependencies.

Example,

web.xml
```xml
<context-param>
  <param-name>governator.bootstrap.class</param-name>
  <param-value>com.myorg.MyBootstrap</param-value>
</context-param>
  
<filter>
    <filter-name>guiceFilter</filter-name>
    <filter-class>com.google.inject.servlet.GuiceFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>guiceFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<listener>
    <listener-class>com.netflix.governator.guice.servlet.GovernatorServletContextListener</listener-class>
</listener>
```

This is the Governator bootstrap enabled class.
```java
@Modules(include={SomeServiceModule.class})
public class MyBootstrap extends AbstractModule {
    protected void configure() { 
        bind(ServletContextListener.class).to(MyServletContextListener.class);
    }
}
```

This is the custom ServletContextListener that can have dependencies injected into it.
```java
public class MyServletContextListener implements ServletContextListener {
    private final SomeService service;

    @Inject
    public MyServletContextListener(SomeService service) {
        this.service = service;
    }
    @Override
    public void contextInitialized(final ServletContextEvent event) {
        service.doSomeStartupTask();
    }
}
```