ISIS-362: upgrading to JMock 2.6.0

* and adding in support for @Never, @Ignoring, @Allowing annotations etc.
  (from github.com/danhaywood/java-testsupport).
* the size of the commit is because of an "organize import" throughout,
  done with respect to our standard isis.importorder
  (see http://isis.apache.org/contributors/development-environment.html)
ISIS-363: max length of titles in tables (for wicket viewer)

* new properties to distinguish between parented and standalone tables.
* also, tiny fix to ToDoItems, specify @Regex on description (was missing in one location).