spring mvc stuff

[paulben]

The springboot starter appears to me to be Spring REST but not Spring MVC as it uses @RestController, which is not the same as a @controller which is generally used for MVC.

This PR contains the changes I made to add an MVC @controller. It's not complete and probably needs design work (probably Spring MVC should be a separate technology from Spring REST?) but I just wanted to save the changes I made - I didn't update test and no doubt didn't dot all the i's and cross all the t's...etc., etc.

It basically:

• adds a thymeleaf html (hello.html) which uses data from the model
• adds a @controller (LibertyMVController.java) which updates the model with a request param
• renames LibertyHelloController.java to LibertyRESTController.java
• updates the compile-pom to add thymeleaf
• updates description.html to reference the new REST and MVC endpoints.

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