Changed viw to include the expense id
Changed amount property of expense from string to double
Added entity style mapping for Expense

Also added mappings for dependant types
Updated bindings on Dataview

The expense table now connects to the entity maaping
Added override of equals to mapped types
Added form for viewing/editing expenses
Connected ExpenseViewer to the data grid

The user can now edit the data after double clicking on it in the data
grid
Refactored the new entity classes into n-tier stlye

Except for expense entity
Refactored Expense entity to n-tier

Also added extension class in framework
Updated the data viewer to refresh the data on refocus
Cleaned up and commented

The code in the BusniessLogic project
Clean up and commenting

The new DataAccess project
Clean up and commenting, closes #12
Merge pull request #26 from M-Zuber/Development

Added feature for updating expense