added the todoHolder class to hold the todo title and the due date.
added alot of things:
1. the input text was deleted from the main activity.
2. added the add activity.
3. delete the delete from the menu.
4. fixed the date representation.
5. added first trail of coloring deu dates.
1. checked the option for date to be null - "No due date" case.
2. made some ui design modifications.
color both the title and the date when the date is over due.
some ui design changes.
1. remove item if it's not starting with "Call "
2. added the call activity.
orgenize code for submit.