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
Jersey 2 has some Spring support built in but it's a bit awkward to
use in a Boot app, so autoconfiguration seems appropriate. The tests
and sample show how to use it, but the short story is that any
@Component can define JAX-RS endpoints via @GET etc.
There's a sample for Jersey 1 as well (pay careful attention to
the plugin configuration if you want to build an executable jar)
Fixes gh-1651