constructor, getters, addNotes.
removed code of ContactManager that I'd put here initially by mistake.  
Moved a comment to FutureMeetingImpl.
moved comment from FutureMeeting to here.
added imports
added imports and 'implements' keyword
added 'implements' keyword
visibility of methods
added addContact(Contact contact) method
added addContact(Contact contact) method
added 'implements' keyword.
Constructor increments static id counter, initialises set of
contacts,adds one contact,new method addContact(ContactImpl contact)
allows more contacts to be added to a meeting one at a time.
added 'implements' keyword and filled getter.
Eclipse default JUnit tests created, plus some other tidying up of
classes and interfaces.