Improved BasicPersistence example

* Fixed -addAppointment: to use the correct multivalued accessor pattern

* Small code improvements (e.g. super initializer call or formatting)

* Reorganized main() to be much more readable and illustrate basic reloading 
as previously (while still printing the entire store contents)


git-svn-id: http://svn.gna.org/svn/etoile/trunk/Etoile/Frameworks/CoreObject@10002 7b3f36aa-e6db-49c1-8b4c-66eac1997e64