XD-293 Ensure package-info.java to all packages

- Add missing `package.info` to all the packages
- Fix/Update javadoc
- Move `org.springframework.xd.dirt.XDRuntimeException`
to `org.springframework.xd.dirt.util.XDRuntimeException`
s/supports/support/

s/job/jobs/

Also, this should definitely all fit on one line.