Implemented db adapters for locations and todos.
Can save a new location created to map in db and fixed nullpointer
exception when exiting map without having found a location.
Finish MapViewActivity only if data is added successfully to db.
Title in new to-do and name in new location should have at least 4
characters.
Added check for max description length.
Now can save new to do to db.
Can use previously saved locations.
Can add locations from main screen.