Added a BillFileRepository to persist bills to local file storage. This is currently the prefered storage of the app.
Fixed some bugs that prevented proper saving and displaying of bills.
Added a Dialog to enter a name for a bill that the user wants to save.
Improved the layout of the save bill dialog.
Implemented removal of bills from bill list.
Display name of bill at the top of the bill fragment.
Renamed 'reset items' to 'new bill' which better fits to the underlying function.
Added method to save profiles to local disk and connected the context menu item of Beermat Activity to that method.
Added new Activity to watch the list of existing profiles.
Removed absolete BillDetail Activity and BillDetailIntent. Existing bills are loaded in the Beermat Activity now.
Reordered the menu in Beermat Activity - new bill entry is now the first one.