Added icons, changed list storage

Bugfix: detail activity menu item titles were wrong.
Adds: database is now closed when the activity is destroyed (detail
activity only).
Adds: icons for alphabetical order and move to bottom options shown in
master activity for each list (if the option is enabled).
Bugfix: clicking on up button in detail activity now properly returns to
master activity.
Adds: original Remi icon is now shown.
Change: lists are no more stored in a sqlite database table and are now
stored in a file using JSON encoding (items are still stored in the good
ol' database... for now).
Adds: now the last clicked list will be moved on top of the view.
Adds: master activity has now a custom array adapter.
Adds: now list names can contain apostophes or any others symboles.