Added detail list click handling

Adds: detail activity now shows a checkbox for each item in the list.
Checks are now properly stored when an item is clicked and loaded when a
list needs to be shown.
Adds: list options now properly influence the order in which items are
shown.
Adds: the search item hint is now "Remember the milk", as in the
original app.
Bugfix: corrected some bugs when creating a new item for the list
(database version is the same).
Bugfix: opening a list now properly shows its items.
Bugfix: modifying a list without changing its name (check/uncheck list
options) can now be done and changes are stored properly.