Replace XML with Java configuration in the booking-mvc and booking-faces samples

The main goal of the switch is to demonstrate the new Java-based configuration option coming to Spring Web Flow 2.4 RC1 (see issue [SWF-1548](https://jira.springsource.org/browse/SWF-1548)).

In addition all other Spring configuration -- Spring Security, Spring MVC, and Database -- has been updated to use Java config. Likewise `web.xml` is replaced with Java-based `DispatcherServletInitializer` (requires Servlet 3.0).

Note that all of these changes are not required. It is possible to [combine Spring XML and Java config](http://docs.spring.io/spring-framework/docs/current/spring-framework-reference/html/beans.html#beans-java-combining) and it is possible to use [web.xml with Spring Java config](https://github.com/spring-projects/spring-framework-issues/tree/master/SPR-0000-war-java).