Batch change xml-config to java config

[sroeger]

As @maihacke proposed we should discuss if we migrate to java config for batch too. In PR #442 I proposed an exemplary batch job configured with java config including skip listeners, access to the application.properties file and a custom editor.
Imho the only drawback is the bad documentation for java config in the official spring batch guide. However, one can find answers in various migration guides. We could add those into the wiki.