Given that Spring Boot uses java config accross the board, a new `value`
attribute is now aliased to the existing `classes` attribute such that
one could write the following:
@SpringApplicationConfiguration(MyConfig.class)
public class MyTest {}
Closes gh-3635
The package names changed a bit from the prototype project, but wuth vanilla
autconfiguration usage that shouldn't matter. Follows closely the Groovy
templates support. Templates live in classpath:/templates/*.html by default.
Fixes gh-2242
