Long package names are really unnecessary in samples and they
just clutter things up. Also Spring Loaded doesn't work with
org.sfw packages, so to demo that technology you need a
different package name.
A side effect is that spring-boot-starter-data-jpa needs
to include an aspectjweaver depdendency. Hope that doesn't
hurt anything else.
[Fixes#56780004]
* Added ExitCodeGenerator and SpringApplication.exit
convenience method
* User can add bean of type ExitCodeGenerator or supply
one in the call to exit()
[Fixes#48475971]