XD-1145. Add --date option to trigger

Please note I couldn't run the integration tests (part of this commit), they all lead to:

`14/01/13 20:55:18 ERROR web.BasicErrorController: java.lang.NoClassDefFoundError: org/springframework/integration/core/MessageHandler`

This error has been reproduced on @ericbottard's laptop.
Finally, it seems I already signed the CLA (for Spring Data, as far as I remember).