ISIS-351, ISIS-379, ISIS-380: remove RecognizedException, move AuditServiceDemo to JDO, enhance BookmarkService

* removed RecognizedException; there's no need for it (it isn't used anywhere) and just complicates the programming model.  Instead, applications should continue to throw the Isis applib's ApplicationException
* moved AuditServiceDemo into JDO objectstore, and renamed to AuditingServiceJdo
* enhanced BookmarkService API so that allows a domain object to be looked up directly, rather than requiring there to be a BookmarkHolder impl
* registered BookmarkServiceDefault with ToDo app services (example for quickstart)
* registered RegisterEntities with ToDo app services (example for quickstart)
ISIS-381: mothballing HTML viewer, SQL security, LDAP security