#21 - Added example for Spring Data REST and Spring Security.

Added example of how to secure a Spring Data REST project with Spring Security both on the method level as well as the URI level.

Original pull request: #22.
#21 - Polished Spring Data REST + Spring Security example.

Removed obsolete dependency declarations from pom.xml. Rewrote test cases to use Spring MVC test support instead of a running server and RestTemplate. Fixed Security configuration to allow bootstrap in Spring MVC test context. Formatting, JavaDoc.

Original pull request: #22.