Thymeleaf 3.0 implements the Spring 5.0 view infrastructure for WebMVC
and the new WebFlux framework. This commit adds auto-configuration for
the WebFlux support.
In that process, the configuration property for `spring.thymeleaf` has
been changed to add `spring.thymeleaf.servlet` and
`spring.thymeleaf.reactive` for MVC/WebFlux specific properties.
Now that the `spring-boot-starter-thymeleaf` does not only support
Spring MVC, the transitive dependency on `spring-boot-starter-web` is
removed from it.
Fixes gh-8124
if user also adds @EnableWebMvcSecurity. The problem is that the ordering
of the init() and configure() methods in the Spring Security configurers
can force things to happen too early unless we are careful. It's still a bit
twitchy I would say, but this relatively small change seems to fix the GS guide
and not break any existing tests.
I added a sample which mimic ths GS guide so we get an integration test that
executes the new code paths.
Fixes gh-1364
