New files:
* `abstract_sql_dao.dart`: DAO abstraction for SQL.
* `bulk_deletable.dart`: Interface for bulk database deletes.
* `bulk_insertable.dart`: Interface for bulk database inserts.
* `bulk_manager.dart`: Manager for bulk database inserts and deletes.
* `dao_hive_product.dart`: moved code from the previous `hive` version of `DaoProduct`, renamed here `DaoHiveProduct`
Impacted files:
* `dao_product.dart`: `sqflite` version of `DaoProduct`, that is from now on the only one to be used
* `local_database.dart`: added `sqflite` and its one table so far, also named `DaoProduct` in order to minimize the changes everywhere else (the old `DaoProduct` being renamed `DaoHiveProduct`); migrated the product data from `hive` to `sqflite`
* `Podfile.lock`: wtf
* `pubspec.lock`: wtf
* `data_importer/pubspec.yaml`: updated the `sqflite` dependency to the same as in `smooth_app`
* `smooth_app/pubspec.yaml`: added a dependency to `sqflite`
Deleted files:
* `bulk_deletable.dart`
* `bulk_insertable.dart`
* `bulk_manager.dart`
* `dao_product_extra.dart`
* `label_sneek_peak_view.dart`
* `list_page.dart`
* `multi_product_select_page.dart`
* `product_copy_helper.dart`
* `product_copy_view.dart`
* `product_extra.dart`
* `product_list_add_button.dart`
* `product_list_button.dart`
* `product_list_item.dart`
* `product_list_item_pantry.dart`
* `product_list_item_shopping.dart`
* `product_list_preview.dart`
* `product_list_preview_helper.dart`
Impacted files:
* `abstract_dao.dart`: added hive related init methods
* `barcode_product_query.dart`: minor refactoring
* `category_product_query.dart`: minor refactoring
* `continuous_scan_model.dart`: minor refactoring
* `dao_product.dart`: rewritten from scratch with hive instead of sqflite - much easier to understand!
* `dao_product_list.dart`: rewritten from scratch with hive instead of sqflite - much easier to understand!
* `dao_string_list.dart` (renamed from `search_history.dart`): rewritten from scratch with hive instead of sqflite
* `database_product_list_supplier.dart`: minor refactoring
* `group_product_query.dart`: minor refactoring
* `history_page.dart`: minor refactoring
* `keywords_product_query.dart`: minor refactoring
* `local_database.dart`: rewritten from scratch with hive instead of sqflite; simplified
* `main.dart`: minor refactoring
* `new_product_page.dart`: minor refactoring
* `personalized_ranking_page.dart`: removed old feature
* `product_list.dart`: preferred `enum` to `String` for types; removed tons of old features
* `product_list_dialog_helper.dart`: removed old feature
* `product_list_item_simple.dart`: removed old features
* `product_list_page.dart`: removed old features
* `product_page.dart`: removed old feature
* `product_query_page_helper.dart`: cleaner code with `enum`s
* `pubspec.yaml`: added hive, removed sqflite
* `query_product_list_supplier.dart`: minor refactoring
* `search_history_view.dart`: minor refactoring
* `search_page.dart`: minor refactoring
Impacted files:
* `bulk_manager.dart`: unrelated - fixed a bug about the number of parameters for bulk insert; `insert` method now returns the number of inserted rows; `delete` method now returns the number of deleted rows
* `dao_product.dart`: added barcode for suggestion if text is number; refactored
* `text_search_widget.dart`: added the barcode to the suggestion results
Database table `product_extra` replaces now dropped `product_list_item`.
New files:
* `bulk_deletable.dart`: Interface for bulk database deletes
* `bulk_insertable.dart`: Interface for bulk database inserts
* `bulk_manager.dart`: Manager for bulk database inserts and deletes
Impacted files:
* `abstract_dao.dart`: moved specific code to new classes `Bulk...`
* `dao_product.dart`: refactored
* `dao_product_extra.dart`: now manages the product list as "product extra"; now implements new interface `BulkDeletable`
* `dao_product_list.dart`: moved the data from table `product_list_item` to table `product_extra`; dropped table `product_list_item`; refactored
* `home_page.dart`: refresh after product list preview
* `list_page.dart`: refresh after product list preview
* `local_database.dart`: new database version
* `multi_select_product_page.dart`: refactored
* `product_copy_helper.dart`: refactored
* `product_list.dart`: added the list reordering feature; refactored
* `product_list_dialog_helper.dart`: refactored
* `product_list_page.dart`: some product lists are now reorderable and with dismissible items
* `product_list_preview.dart`: added the `andThen` parameter for a refresh afterwards
* `product_page.dart`: minor fix
* `query_product_list_supplier.dart`: refactored
* `smooth_it_model.dart`: refactored
