ISIS-651: make JDO PMF accessible, invalidateCache signature

in addition:
- sorted out .launch files for ToDo app and Simple app, added to appropriate favourites.
ISIS-648, ISIS-652, ISIS-653, ISIS-655: bulk actions, request scoped services

ISIS-652: @RequestScoped services
- CDI 1.0 now a dependency of applib (for the @RequestScoped annotation)
- javassist is now a dependency of runtime
- ServiceInitializer, create javassist proxy for request-scoped services/beans
  (delegates to threadlocal held within the proxy)
- functionality in JavassistClassSubstitor now moved into core (ClassSubstitutorAbstract) so that
  ObjectSpecifications for @RequestScoped services are automatically setup correctly
  (the synthetic methods etc are disregarded)
- old JavassistClassSubstitor in core-bytecode-javassist now marked as deprecated
- PersistenceSession#open automatically initializes all request-scoped services (by downcasting to RequestScopedService and
  calling __isis_startRequest), and #close() similarly tidies up (by calling to __isis_endRequest)
- UserProfileLoaderDefault, when creating the UserProfile object, excludes any request-scoped services

ISIS-648, ISIS-655: enhanced bulk update support
- @Bulk#appliesTo property - whether to render action *only* as bulk
  - updates to EntityActionUtil to suppress in UI
- Bulk.InteractionContext#invokedAs added, to tell object whether the action called as a bulk or regular
- change in behaviour when invoking bulk actions, navigate to return value of action of last object called (if not null)
- ActionResultResponseType (etc) factored out for common handling of results from either
  regular actions or bulk actions

ISIS-655, refactored bulk interaction context
- Bulk.InteractionContext is now a request scoped service
  - deprecated the old threadlocal current
  - PersistenceSession#open copies over the service to the threadlocal
- deprecated Bulk.InteractionContext#with(...) methods
  - no longer required, so throw an explanatory exception (yes, this is a tiny breaking change...)

ISIS-653, Scratchpad @RequestScoped service
- Scratchpad service to get and set userdata, added to applib
  - allows apps to pass contextual information from one object's action to next
- TodoItem updated to demonstrate usage