Update to Image Cache to be more coarse grain when it comes to
synchronization
Changed Max image length to be 400 instead of 600
Updated Restaurant to support finding a dining session that has a
particular user or that has a particular Table ID.  DiningSession can
now check if it has a user inside
Refactored ImageGetCallback out of inner class and made standalone
interface.  its more understandable
Update Date format for storing dates
Update Order to hold a map of menu items to Integers instead a list of
current order items
Updates to dineOnUser support check if non empty pending order exists.
Add shopping cart image
Added new images to support shopping cart trend
Dining Sessions and Orders now support their own cost generation
Udpates to dining session and order to encapsulate cost behavior
Updates to Menu Item and profile of the Restaurant.  Pretty much update
everything
Current Changes to handle the User Control Flow changes