edited address seq. definition.
Updated entity to reflect new data model.
Updated example.
Updated the sequence id definitions.
Updated the sequence id allocation strategy.

Now the Address sequence ids are being cached (50 at a time). This will however cause me to lose
the first 49 ids from this sequence, but I think I can live with that.
Updated example.

Updated the insert example in main to test the id values that are being generated when changing
the id allocation size for a sequence.
Created employee entity.